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apache / httpd / 9e3a1fcd41146a0fbaf6f572a3a2502383b29f19 / . / modules / ssl / ssl_util_table.c
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/* _ _
** _ __ ___ ___ __| | ___ ___| | mod_ssl
** | '_ ` _ \ / _ \ / _` | / __/ __| | Apache Interface to OpenSSL
** | | | | | | (_) | (_| | \__ \__ \ | www.modssl.org
** |_| |_| |_|\___/ \__,_|___|___/___/_| ftp.modssl.org
** |_____|
** ssl_util_table.c
** High Performance Hash Table Functions
*/
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*/
/*
* Generic hash table handler
* Table 4.1.0 July-28-1998
*
* This library is a generic open hash table with buckets and
* linked lists. It is pretty high performance. Each element
* has a key and a data. The user indexes on the key to find the
* data.
*
* Copyright 1998 by Gray Watson <gray@letters.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose and without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies,
* and that the name of Gray Watson not be used in advertising or
* publicity pertaining to distribution of the document or software
* without specific, written prior permission.
*
* Gray Watson makes no representations about the suitability of the
* software described herein for any purpose. It is provided "as is"
* without express or implied warranty.
*
* Modified in March 1999 by Ralf S. Engelschall <rse@engelschall.com>
* for use in the mod_ssl project:
* o merged table_loc.h header into table.c
* o removed fillproto-comments from table.h
* o removed mmap() support because it's too unportable
* o added support for MM library via ta_{malloc,calloc,realloc,free}
*/
#include <stdlib.h>
#include <string.h>
/* forward definitions for table.h */
typedef struct table_st table_t;
typedef struct table_entry_st table_entry_t;
#define TABLE_PRIVATE
#include "ssl_util_table.h"
#include "mod_ssl.h"
/****************************** local defines ******************************/
#ifndef BITSPERBYTE
#define BITSPERBYTE 8
#endif
#ifndef BITS
#define BITS(type) (BITSPERBYTE * (int)sizeof(type))
#endif
#define TABLE_MAGIC 0xBADF00D /* very magic magicness */
#define LINEAR_MAGIC 0xAD00D00 /* magic value for linear struct */
#define DEFAULT_SIZE 1024 /* default table size */
#define MAX_ALIGNMENT 128 /* max alignment value */
#define MAX_SORT_SPLITS 128 /* qsort can handle 2^128 entries */
/* returns 1 when we should grow or shrink the table */
#define SHOULD_TABLE_GROW(tab) ((tab)->ta_entry_n > (tab)->ta_bucket_n * 2)
#define SHOULD_TABLE_SHRINK(tab) ((tab)->ta_entry_n < (tab)->ta_bucket_n / 2)
/*
* void HASH_MIX
*
* DESCRIPTION:
*
* Mix 3 32-bit values reversibly. For every delta with one or two bits
* set, and the deltas of all three high bits or all three low bits,
* whether the original value of a,b,c is almost all zero or is
* uniformly distributed.
*
* If HASH_MIX() is run forward or backward, at least 32 bits in a,b,c
* have at least 1/4 probability of changing. If mix() is run
* forward, every bit of c will change between 1/3 and 2/3 of the
* time. (Well, 22/100 and 78/100 for some 2-bit deltas.)
*
* HASH_MIX() takes 36 machine instructions, but only 18 cycles on a
* superscalar machine (like a Pentium or a Sparc). No faster mixer
* seems to work, that's the result of my brute-force search. There
* were about 2^68 hashes to choose from. I only tested about a
* billion of those.
*/
#define HASH_MIX(a, b, c) \
do { \
a -= b; a -= c; a ^= (c >> 13); \
b -= c; b -= a; b ^= (a << 8); \
c -= a; c -= b; c ^= (b >> 13); \
a -= b; a -= c; a ^= (c >> 12); \
b -= c; b -= a; b ^= (a << 16); \
c -= a; c -= b; c ^= (b >> 5); \
a -= b; a -= c; a ^= (c >> 3); \
b -= c; b -= a; b ^= (a << 10); \
c -= a; c -= b; c ^= (b >> 15); \
} while(0)
#define TABLE_POINTER(table, type, pnt) (pnt)
/*
* Macros to get at the key and the data pointers
*/
#define ENTRY_KEY_BUF(entry_p) ((entry_p)->te_key_buf)
#define ENTRY_DATA_BUF(tab_p, entry_p) \
(ENTRY_KEY_BUF(entry_p) + (entry_p)->te_key_size)
/*
* Table structures...
*/
/*
* HACK: this should be equiv as the table_entry_t without the key_buf
* char. We use this with the ENTRY_SIZE() macro above which solves
* the problem with the lack of the [0] GNU hack. We use the
* table_entry_t structure to better map the memory and make things
* faster.
*/
typedef struct table_shell_st {
unsigned int te_key_size; /* size of data */
unsigned int te_data_size; /* size of data */
struct table_shell_st *te_next_p; /* pointer to next in the list */
/* NOTE: this does not have the te_key_buf field here */
} table_shell_t;
/*
* Elements in the bucket linked-lists. The key[1] is the start of
* the key with the rest of the key and all of the data information
* packed in memory directly after the end of this structure.
*
* NOTE: if this structure is changed, the table_shell_t must be changed
* to match.
*/
struct table_entry_st {
unsigned int te_key_size; /* size of data */
unsigned int te_data_size; /* size of data */
struct table_entry_st *te_next_p; /* pointer to next in the list */
unsigned char te_key_buf[1]; /* 1st byte of key buf */
};
/* external structure for debuggers be able to see void */
typedef table_entry_t table_entry_ext_t;
/* main table structure */
struct table_st {
unsigned int ta_magic; /* magic number */
unsigned int ta_flags; /* table's flags defined in table.h */
unsigned int ta_bucket_n; /* num of buckets, should be 2^X */
unsigned int ta_entry_n; /* num of entries in all buckets */
unsigned int ta_data_align; /* data alignment value */
table_entry_t **ta_buckets; /* array of linked lists */
table_linear_t ta_linear; /* linear tracking */
unsigned long ta_file_size; /* size of on-disk space */
void *(*ta_malloc)(void *opt_param, size_t size);
void *(*ta_calloc)(void *opt_param, size_t number, size_t size);
void *(*ta_realloc)(void *opt_param, void *ptr, size_t size);
void (*ta_free)(void *opt_param, void *ptr);
void *opt_param;
};
/* external table structure for debuggers */
typedef table_t table_ext_t;
/* local comparison functions */
typedef int (*compare_t) (const void *element1_p, const void *element2_p,
table_compare_t user_compare,
const table_t * table_p);
/*
* to map error to string
*/
typedef struct {
int es_error; /* error number */
char *es_string; /* assocaited string */
} error_str_t;
static error_str_t errors[] =
{
{TABLE_ERROR_NONE, "no error"},
{TABLE_ERROR_PNT, "invalid table pointer"},
{TABLE_ERROR_ARG_NULL, "buffer argument is null"},
{TABLE_ERROR_SIZE, "incorrect size argument"},
{TABLE_ERROR_OVERWRITE, "key exists and no overwrite"},
{TABLE_ERROR_NOT_FOUND, "key does not exist"},
{TABLE_ERROR_ALLOC, "error allocating memory"},
{TABLE_ERROR_LINEAR, "linear access not in progress"},
{TABLE_ERROR_OPEN, "could not open file"},
{TABLE_ERROR_SEEK, "could not seek to position in file"},
{TABLE_ERROR_READ, "could not read from file"},
{TABLE_ERROR_WRITE, "could not write to file"},
{TABLE_ERROR_EMPTY, "table is empty"},
{TABLE_ERROR_NOT_EMPTY, "table contains data"},
{TABLE_ERROR_ALIGNMENT, "invalid alignment value"},
{0}
};
#define INVALID_ERROR "invalid error code"
/********************** wrappers for system functions ************************/
static void *sys_malloc(void *param, size_t size)
{
return malloc(size);
}
static void *sys_calloc(void *param, size_t size1, size_t size2)
{
return calloc(size1, size2);
}
static void *sys_realloc(void *param, void *ptr, size_t size)
{
return realloc(ptr, size);
}
static void sys_free(void *param, void *ptr)
{
free(ptr);
}
/****************************** local functions ******************************/
/*
* static table_entry_t *first_entry
*
* DESCRIPTION:
*
* Return the first entry in the table. It will set the linear
* structure counter to the position of the first entry.
*
* RETURNS:
*
* Success: A pointer to the first entry in the table.
*
* Failure: NULL if there is no first entry.
*
* ARGUMENTS:
*
* table_p - Table whose next entry we are finding.
*
* linear_p - Pointer to a linear structure which we will advance and
* then find the corresponding entry.
*/
static table_entry_t *first_entry(table_t * table_p,
table_linear_t * linear_p)
{
table_entry_t *entry_p;
unsigned int bucket_c = 0;
/* look for the first non-empty bucket */
for (bucket_c = 0; bucket_c < table_p->ta_bucket_n; bucket_c++) {
entry_p = table_p->ta_buckets[bucket_c];
if (entry_p != NULL) {
if (linear_p != NULL) {
linear_p->tl_bucket_c = bucket_c;
linear_p->tl_entry_c = 0;
}
return TABLE_POINTER(table_p, table_entry_t *, entry_p);
}
}
return NULL;
}
/*
* static table_entry_t *next_entry
*
* DESCRIPTION:
*
* Return the next entry in the table which is past the position in
* our linear pointer. It will advance the linear structure counters.
*
* RETURNS:
*
* Success: A pointer to the next entry in the table.
*
* Failure: NULL.
*
* ARGUMENTS:
*
* table_p - Table whose next entry we are finding.
*
* linear_p - Pointer to a linear structure which we will advance and
* then find the corresponding entry.
*
* error_p - Pointer to an integer which when the routine returns will
* contain a table error code.
*/
static table_entry_t *next_entry(table_t * table_p, table_linear_t * linear_p,
int *error_p)
{
table_entry_t *entry_p;
int entry_c;
/* can't next if we haven't first-ed */
if (linear_p == NULL) {
if (error_p != NULL)
*error_p = TABLE_ERROR_LINEAR;
return NULL;
}
if (linear_p->tl_bucket_c >= table_p->ta_bucket_n) {
/*
* NOTE: this might happen if we delete an item which shortens the
* table bucket numbers.
*/
if (error_p != NULL)
*error_p = TABLE_ERROR_NOT_FOUND;
return NULL;
}
linear_p->tl_entry_c++;
/* find the entry which is the nth in the list */
entry_p = table_p->ta_buckets[linear_p->tl_bucket_c];
/* NOTE: we swap the order here to be more efficient */
for (entry_c = linear_p->tl_entry_c; entry_c > 0; entry_c--) {
/* did we reach the end of the list? */
if (entry_p == NULL)
break;
entry_p = TABLE_POINTER(table_p, table_entry_t *, entry_p)->te_next_p;
}
/* did we find an entry in the current bucket? */
if (entry_p != NULL) {
if (error_p != NULL)
*error_p = TABLE_ERROR_NONE;
return TABLE_POINTER(table_p, table_entry_t *, entry_p);
}
/* find the first entry in the next non-empty bucket */
linear_p->tl_entry_c = 0;
for (linear_p->tl_bucket_c++; linear_p->tl_bucket_c < table_p->ta_bucket_n;
linear_p->tl_bucket_c++) {
entry_p = table_p->ta_buckets[linear_p->tl_bucket_c];
if (entry_p != NULL) {
if (error_p != NULL)
*error_p = TABLE_ERROR_NONE;
return TABLE_POINTER(table_p, table_entry_t *, entry_p);
}
}
if (error_p != NULL)
*error_p = TABLE_ERROR_NOT_FOUND;
return NULL;
}
/*
* static unsigned int hash
*
* DESCRIPTION:
*
* Hash a variable-length key into a 32-bit value. Every bit of the
* key affects every bit of the return value. Every 1-bit and 2-bit
* delta achieves avalanche. About (6 * len + 35) instructions. The
* best hash table sizes are powers of 2. There is no need to use mod
* (sooo slow!). If you need less than 32 bits, use a bitmask. For
* example, if you need only 10 bits, do h = (h & hashmask(10)); In
* which case, the hash table should have hashsize(10) elements.
*
* By Bob Jenkins, 1996. bob_jenkins@compuserve.com. You may use
* this code any way you wish, private, educational, or commercial.
* It's free. See
* http://ourworld.compuserve.com/homepages/bob_jenkins/evahash.htm
* Use for hash table lookup, or anything where one collision in 2^^32
* is acceptable. Do NOT use for cryptographic purposes.
*
* RETURNS:
*
* Returns a 32-bit hash value.
*
* ARGUMENTS:
*
* key - Key (the unaligned variable-length array of bytes) that we
* are hashing.
*
* length - Length of the key in bytes.
*
* init_val - Initialization value of the hash if you need to hash a
* number of strings together. For instance, if you are hashing N
* strings (unsigned char **)keys, do it like this:
*
* for (i=0, h=0; i<N; ++i) h = hash( keys[i], len[i], h);
*/
static unsigned int hash(const unsigned char *key,
const unsigned int length,
const unsigned int init_val)
{
const unsigned char *key_p = key;
unsigned int a, b, c, len;
/* set up the internal state */
a = 0x9e3779b9; /* the golden ratio; an arbitrary value */
b = 0x9e3779b9;
c = init_val; /* the previous hash value */
/* handle most of the key */
for (len = length; len >= 12; len -= 12) {
a += (key_p[0]
+ ((unsigned long) key_p[1] << 8)
+ ((unsigned long) key_p[2] << 16)
+ ((unsigned long) key_p[3] << 24));
b += (key_p[4]
+ ((unsigned long) key_p[5] << 8)
+ ((unsigned long) key_p[6] << 16)
+ ((unsigned long) key_p[7] << 24));
c += (key_p[8]
+ ((unsigned long) key_p[9] << 8)
+ ((unsigned long) key_p[10] << 16)
+ ((unsigned long) key_p[11] << 24));
HASH_MIX(a, b, c);
key_p += 12;
}
c += length;
/* all the case statements fall through to the next */
switch (len) {
case 11:
c += ((unsigned long) key_p[10] << 24);
case 10:
c += ((unsigned long) key_p[9] << 16);
case 9:
c += ((unsigned long) key_p[8] << 8);
/* the first byte of c is reserved for the length */
case 8:
b += ((unsigned long) key_p[7] << 24);
case 7:
b += ((unsigned long) key_p[6] << 16);
case 6:
b += ((unsigned long) key_p[5] << 8);
case 5:
b += key_p[4];
case 4:
a += ((unsigned long) key_p[3] << 24);
case 3:
a += ((unsigned long) key_p[2] << 16);
case 2:
a += ((unsigned long) key_p[1] << 8);
case 1:
a += key_p[0];
/* case 0: nothing left to add */
}
HASH_MIX(a, b, c);
return c;
}
/*
* static int entry_size
*
* DESCRIPTION:
*
* Calculates the appropriate size of an entry to include the key and
* data sizes as well as any associated alignment to the data.
*
* RETURNS:
*
* The associated size of the entry.
*
* ARGUMENTS:
*
* table_p - Table associated with the entries whose size we are
* determining.
*
* key_size - Size of the entry key.
*
* data - Size of the entry data.
*/
static int entry_size(const table_t * table_p, const unsigned int key_size,
const unsigned int data_size)
{
int size, left;
/* initial size -- key is already aligned if right after struct */
size = sizeof(struct table_shell_st) + key_size;
/* if there is no alignment then it is easy */
if (table_p->ta_data_align == 0)
return size + data_size;
/* add in our alignement */
left = size & (table_p->ta_data_align - 1);
if (left > 0)
size += table_p->ta_data_align - left;
/* we add the data size here after the alignment */
size += data_size;
return size;
}
/*
* static unsigned char *entry_data_buf
*
* DESCRIPTION:
*
* Companion to the ENTRY_DATA_BUF macro but this handles any
* associated alignment to the data in the entry.
*
* RETURNS:
*
* Pointer to the data segment of the entry.
*
* ARGUMENTS:
*
* table_p - Table associated with the entry.
*
* entry_p - Entry whose data pointer we are determining.
*/
static unsigned char *entry_data_buf(const table_t * table_p,
const table_entry_t * entry_p)
{
const unsigned char *buf_p;
int size, pad;
buf_p = entry_p->te_key_buf + entry_p->te_key_size;
/* if there is no alignment then it is easy */
if (table_p->ta_data_align == 0)
return (unsigned char *) buf_p;
/* we need the size of the space before the data */
size = sizeof(struct table_shell_st) + entry_p->te_key_size;
/* add in our alignment */
pad = size & (table_p->ta_data_align - 1);
if (pad > 0)
pad = table_p->ta_data_align - pad;
return (unsigned char *) buf_p + pad;
}
/******************************* sort routines *******************************/
/*
* static int our_compare
*
* DESCRIPTION:
*
* Compare two entries by calling user's compare program or by using
* memcmp.
*
* RETURNS:
*
* < 0, == 0, or > 0 depending on whether p1 is > p2, == p2, < p2.
*
* ARGUMENTS:
*
* p1 - First entry pointer to compare.
*
* p2 - Second entry pointer to compare.
*
* compare - User comparison function. Ignored.
*
* table_p - Associated table being ordered. Ignored.
*/
static int local_compare(const void *p1, const void *p2,
table_compare_t compare, const table_t * table_p)
{
const table_entry_t *const *ent1_p = p1, *const *ent2_p = p2;
int cmp;
unsigned int size;
/* compare as many bytes as we can */
size = (*ent1_p)->te_key_size;
if ((*ent2_p)->te_key_size < size)
size = (*ent2_p)->te_key_size;
cmp = memcmp(ENTRY_KEY_BUF(*ent1_p), ENTRY_KEY_BUF(*ent2_p), size);
/* if common-size equal, then if next more bytes, it is larger */
if (cmp == 0)
cmp = (*ent1_p)->te_key_size - (*ent2_p)->te_key_size;
return cmp;
}
/*
* static int external_compare
*
* DESCRIPTION:
*
* Compare two entries by calling user's compare program or by using
* memcmp.
*
* RETURNS:
*
* < 0, == 0, or > 0 depending on whether p1 is > p2, == p2, < p2.
*
* ARGUMENTS:
*
* p1 - First entry pointer to compare.
*
* p2 - Second entry pointer to compare.
*
* user_compare - User comparison function.
*
* table_p - Associated table being ordered.
*/
static int external_compare(const void *p1, const void *p2,
table_compare_t user_compare,
const table_t * table_p)
{
const table_entry_t *const *ent1_p = p1, *const *ent2_p = p2;
/* since we know we are not aligned we can use the EXTRY_DATA_BUF macro */
return user_compare(ENTRY_KEY_BUF(*ent1_p), (*ent1_p)->te_key_size,
ENTRY_DATA_BUF(table_p, *ent1_p),
(*ent1_p)->te_data_size,
ENTRY_KEY_BUF(*ent2_p), (*ent2_p)->te_key_size,
ENTRY_DATA_BUF(table_p, *ent2_p),
(*ent2_p)->te_data_size);
}
/*
* static int external_compare_align
*
* DESCRIPTION:
*
* Compare two entries by calling user's compare program or by using
* memcmp. Alignment information is necessary.
*
* RETURNS:
*
* < 0, == 0, or > 0 depending on whether p1 is > p2, == p2, < p2.
*
* ARGUMENTS:
*
* p1 - First entry pointer to compare.
*
* p2 - Second entry pointer to compare.
*
* user_compare - User comparison function.
*
* table_p - Associated table being ordered.
*/
static int external_compare_align(const void *p1, const void *p2,
table_compare_t user_compare,
const table_t * table_p)
{
const table_entry_t *const *ent1_p = p1, *const *ent2_p = p2;
/* since we are aligned we have to use the entry_data_buf function */
return user_compare(ENTRY_KEY_BUF(*ent1_p), (*ent1_p)->te_key_size,
entry_data_buf(table_p, *ent1_p),
(*ent1_p)->te_data_size,
ENTRY_KEY_BUF(*ent2_p), (*ent2_p)->te_key_size,
entry_data_buf(table_p, *ent2_p),
(*ent2_p)->te_data_size);
}
/*
* static void split
*
* DESCRIPTION:
*
* This sorts an array of longs via the quick sort algorithm (it's
* pretty quick)
*
* RETURNS:
*
* None.
*
* ARGUMENTS:
*
* first_p - Start of the list that we are splitting.
*
* last_p - Last entry in the list that we are splitting.
*
* compare - Comparison function which is handling the actual
* elements. This is either a local function or a function to setup
* the problem element key and data pointers which then hands off to
* the user function.
*
* user_compare - User comparison function. Could be NULL if we are
* just using a local comparison function.
*
* table_p - Associated table being sorted.
*/
static void split(void *first_p, void *last_p, compare_t compare,
table_compare_t user_compare, table_t * table_p)
{
void *pivot_p, *left_p, *right_p, *left_last_p, *right_first_p;
void *firsts[MAX_SORT_SPLITS], *lasts[MAX_SORT_SPLITS];
int split_c = 0;
for (;;) {
/* no need to split the list if it is < 2 elements */
while (first_p >= last_p) {
if (split_c == 0) {
/* we are done */
return;
}
split_c--;
first_p = firsts[split_c];
last_p = lasts[split_c];
}
left_p = first_p;
right_p = last_p;
pivot_p = first_p;
do {
/* scan from right hand side */
while (right_p > left_p
&& compare(right_p, pivot_p, user_compare, table_p) > 0)
right_p = (char *) right_p - sizeof(table_entry_t *);
/* scan from left hand side */
while (right_p > left_p
&& compare(pivot_p, left_p, user_compare, table_p) >= 0)
left_p = (char *) left_p + sizeof(table_entry_t *);
/* if the pointers haven't met then swap values */
if (right_p > left_p) {
/* swap_bytes(left_p, right_p) */
table_entry_t *temp;
temp = *(table_entry_t **) left_p;
*(table_entry_t **) left_p = *(table_entry_t **) right_p;
*(table_entry_t **) right_p = temp;
}
} while (right_p > left_p);
/* now we swap the pivot with the right-hand side */
{
/* swap_bytes(pivot_p, right_p); */
table_entry_t *temp;
temp = *(table_entry_t **) pivot_p;
*(table_entry_t **) pivot_p = *(table_entry_t **) right_p;
*(table_entry_t **) right_p = temp;
}
pivot_p = right_p;
/* save the section to the right of the pivot in our stack */
right_first_p = (char *) pivot_p + sizeof(table_entry_t *);
left_last_p = (char *) pivot_p - sizeof(table_entry_t *);
/* do we need to save the righthand side? */
if (right_first_p < last_p) {
if (split_c >= MAX_SORT_SPLITS) {
/* sanity check here -- we should never get here */
abort();
}
firsts[split_c] = right_first_p;
lasts[split_c] = last_p;
split_c++;
}
/* do the left hand side of the pivot */
/* first_p = first_p */
last_p = left_last_p;
}
}
/*************************** exported routines *******************************/
/*
* table_t *table_alloc
*
* DESCRIPTION:
*
* Allocate a new table structure.
*
* RETURNS:
*
* A pointer to the new table structure which must be passed to
* table_free to be deallocated. On error a NULL is returned.
*
* ARGUMENTS:
*
* bucket_n - Number of buckets for the hash table. Our current hash
* value works best with base two numbers. Set to 0 to take the
* library default of 1024.
*
* error_p - Pointer to an integer which, if not NULL, will contain a
* table error code.
*
* malloc_f, realloc_f, free_f - Pointers to malloc(3)-, realloc(3)-
* and free(3)-style functions.
*/
table_t *table_alloc(const unsigned int bucket_n, int *error_p,
void *(*malloc_f)(void *opt_param, size_t size),
void *(*calloc_f)(void *opt_param, size_t number, size_t size),
void *(*realloc_f)(void *opt_param, void *ptr, size_t size),
void (*free_f)(void *opt_param, void *ptr), void *opt_param)
{
table_t *table_p = NULL;
unsigned int buck_n;
/* allocate a table structure */
if (malloc_f != NULL)
table_p = malloc_f(opt_param, sizeof(table_t));
else
table_p = malloc(sizeof(table_t));
if (table_p == NULL) {
if (error_p != NULL)
*error_p = TABLE_ERROR_ALLOC;
return NULL;
}
if (bucket_n > 0)
buck_n = bucket_n;
else
buck_n = DEFAULT_SIZE;
/* allocate the buckets which are NULLed */
if (calloc_f != NULL)
table_p->ta_buckets = (table_entry_t **)calloc_f(opt_param, buck_n,
sizeof(table_entry_t *));
else
table_p->ta_buckets = (table_entry_t **)calloc(buck_n, sizeof(table_entry_t *));
if (table_p->ta_buckets == NULL) {
if (error_p != NULL)
*error_p = TABLE_ERROR_ALLOC;
if (free_f != NULL)
free_f(opt_param, table_p);
else
free(table_p);
return NULL;
}
/* initialize structure */
table_p->ta_magic = TABLE_MAGIC;
table_p->ta_flags = 0;
table_p->ta_bucket_n = buck_n;
table_p->ta_entry_n = 0;
table_p->ta_data_align = 0;
table_p->ta_linear.tl_magic = 0;
table_p->ta_linear.tl_bucket_c = 0;
table_p->ta_linear.tl_entry_c = 0;
table_p->ta_file_size = 0;
table_p->ta_malloc = malloc_f != NULL ? malloc_f : sys_malloc;
table_p->ta_calloc = calloc_f != NULL ? calloc_f : sys_calloc;
table_p->ta_realloc = realloc_f != NULL ? realloc_f : sys_realloc;
table_p->ta_free = free_f != NULL ? free_f : sys_free;
table_p->opt_param = opt_param;
if (error_p != NULL)
*error_p = TABLE_ERROR_NONE;
return table_p;
}
/*
* int table_attr
*
* DESCRIPTION:
*
* Set the attributes for the table. The available attributes are
* specified at the top of table.h.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Pointer to a table structure which we will be altering.
*
* attr - Attribute(s) that we will be applying to the table.
*/
int table_attr(table_t * table_p, const int attr)
{
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
table_p->ta_flags = attr;
return TABLE_ERROR_NONE;
}
/*
* int table_set_data_alignment
*
* DESCRIPTION:
*
* Set the alignment for the data in the table. For data elements
* sizeof(long) is recommended unless you use smaller data types
* exclusively.
*
* WARNING: This must be done before any data gets put into the table.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Pointer to a table structure which we will be altering.
*
* alignment - Alignment requested for the data. Must be a power of
* 2. Set to 0 for none.
*/
int table_set_data_alignment(table_t * table_p, const int alignment)
{
int val;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (table_p->ta_entry_n > 0)
return TABLE_ERROR_NOT_EMPTY;
/* defaults */
if (alignment < 2)
table_p->ta_data_align = 0;
else {
/* verify we have a base 2 number */
for (val = 2; val < MAX_ALIGNMENT; val *= 2) {
if (val == alignment)
break;
}
if (val >= MAX_ALIGNMENT)
return TABLE_ERROR_ALIGNMENT;
table_p->ta_data_align = alignment;
}
return TABLE_ERROR_NONE;
}
/*
* int table_clear
*
* DESCRIPTION:
*
* Clear out and free all elements in a table structure.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer that we will be clearing.
*/
int table_clear(table_t * table_p)
{
#if 0
table_entry_t *entry_p, *next_p;
#endif
table_entry_t **bucket_p, **bounds_p;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
/* free the table allocation and table structure */
bounds_p = table_p->ta_buckets + table_p->ta_bucket_n;
for (bucket_p = table_p->ta_buckets; bucket_p <= bounds_p; bucket_p++) {
#if 0
for (entry_p = *bucket_p; entry_p != NULL; entry_p = next_p) {
/* record the next pointer before we free */
next_p = entry_p->te_next_p;
table_p->ta_free(table_p->opt_param, entry_p);
}
#endif
/* clear the bucket entry after we free its entries */
*bucket_p = NULL;
}
/* reset table state info */
table_p->ta_entry_n = 0;
table_p->ta_linear.tl_magic = 0;
table_p->ta_linear.tl_bucket_c = 0;
table_p->ta_linear.tl_entry_c = 0;
return TABLE_ERROR_NONE;
}
/*
* int table_free
*
* DESCRIPTION:
*
* Deallocates a table structure.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer that we will be freeing.
*/
int table_free(table_t * table_p)
{
int ret;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
ret = table_clear(table_p);
if (table_p->ta_buckets != NULL)
table_p->ta_free(table_p->opt_param, table_p->ta_buckets);
table_p->ta_magic = 0;
table_p->ta_free(table_p->opt_param, table_p);
return ret;
}
/*
* int table_insert_kd
*
* DESCRIPTION:
*
* Like table_insert except it passes back a pointer to the key and
* the data buffers after they have been inserted into the table
* structure.
*
* This routine adds a key/data pair both of which are made up of a
* buffer of bytes and an associated size. Both the key and the data
* will be copied into buffers allocated inside the table. If the key
* exists already, the associated data will be replaced if the
* overwrite flag is set, otherwise an error is returned.
*
* NOTE: be very careful changing the values since the table library
* provides the pointers to its memory. The key can _never_ be
* changed otherwise you will not find it again. The data can be
* changed but its length can never be altered unless you delete and
* re-insert it into the table.
*
* WARNING: The pointers to the key and data are not in any specific
* alignment. Accessing the key and/or data as an short, integer, or
* long pointer directly can cause problems.
*
* WARNING: Replacing a data cell (not inserting) will cause the table
* linked list to be temporarily invalid. Care must be taken with
* multiple threaded programs which are relying on the first/next
* linked list to be always valid.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer into which we will be inserting a
* new key/data pair.
*
* key_buf - Buffer of bytes of the key that we are inserting. If you
* are storing an (int) as the key (for example) then key_buf should
* be a (int *).
*
* key_size - Size of the key_buf buffer. If set to < 0 then the
* library will do a strlen of key_buf and add 1 for the '\0'. If you
* are storing an (int) as the key (for example) then key_size should
* be sizeof(int).
*
* data_buf - Buffer of bytes of the data that we are inserting. If
* it is NULL then the library will allocate space for the data in the
* table without copying in any information. If data_buf is NULL and
* data_size is 0 then the library will associate a NULL data pointer
* with the key. If you are storing a (long) as the data (for
* example) then data_buf should be a (long *).
*
* data_size - Size of the data_buf buffer. If set to < 0 then the
* library will do a strlen of data_buf and add 1 for the '\0'. If
* you are storing an (long) as the key (for example) then key_size
* should be sizeof(long).
*
* key_buf_p - Pointer which, if not NULL, will be set to the address
* of the key storage that was allocated in the table. If you are
* storing an (int) as the key (for example) then key_buf_p should be
* (int **) i.e. the address of a (int *).
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that was allocated in the table. If you are
* storing an (long) as the data (for example) then data_buf_p should
* be (long **) i.e. the address of a (long *).
*
* overwrite - Flag which, if set to 1, will allow the overwriting of
* the data in the table with the new data if the key already exists
* in the table.
*/
int table_insert_kd(table_t * table_p,
const void *key_buf, const int key_size,
const void *data_buf, const int data_size,
void **key_buf_p, void **data_buf_p,
const char overwrite_b)
{
int bucket;
unsigned int ksize, dsize;
table_entry_t *entry_p, *last_p;
void *key_copy_p, *data_copy_p;
/* check the arguments */
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (key_buf == NULL)
return TABLE_ERROR_ARG_NULL;
/* data_buf can be null but size must be >= 0, if it isn't null size != 0 */
if ((data_buf == NULL && data_size < 0)
|| (data_buf != NULL && data_size == 0))
return TABLE_ERROR_SIZE;
/* determine sizes of key and data */
if (key_size < 0)
ksize = strlen((char *) key_buf) + sizeof(char);
else
ksize = key_size;
if (data_size < 0)
dsize = strlen((char *) data_buf) + sizeof(char);
else
dsize = data_size;
/* get the bucket number via a hash function */
bucket = hash(key_buf, ksize, 0) % table_p->ta_bucket_n;
/* look for the entry in this bucket, only check keys of the same size */
last_p = NULL;
for (entry_p = table_p->ta_buckets[bucket];
(entry_p != NULL) && (entry_p->te_next_p != last_p);
last_p = entry_p, entry_p = entry_p->te_next_p) {
if (entry_p->te_key_size == ksize
&& memcmp(ENTRY_KEY_BUF(entry_p), key_buf, ksize) == 0)
break;
}
/* did we find it? then we are in replace mode. */
if (entry_p != NULL) {
/* can we not overwrite existing data? */
if (!overwrite_b) {
if (key_buf_p != NULL)
*key_buf_p = ENTRY_KEY_BUF(entry_p);
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
if (table_p->ta_data_align == 0)
*data_buf_p = ENTRY_DATA_BUF(table_p, entry_p);
else
*data_buf_p = entry_data_buf(table_p, entry_p);
}
}
return TABLE_ERROR_OVERWRITE;
}
/* re-alloc entry's data if the new size != the old */
if (dsize != entry_p->te_data_size) {
/*
* First we delete it from the list to keep the list whole.
* This properly preserves the linked list in case we have a
* thread marching through the linked list while we are
* inserting. Maybe this is an unnecessary protection but it
* should not harm that much.
*/
if (last_p == NULL)
table_p->ta_buckets[bucket] = entry_p->te_next_p;
else
last_p->te_next_p = entry_p->te_next_p;
/*
* Realloc the structure which may change its pointer. NOTE:
* this may change any previous data_key_p and data_copy_p
* pointers.
*/
entry_p = (table_entry_t *)
table_p->ta_realloc(table_p->opt_param, entry_p,
entry_size(table_p, entry_p->te_key_size, dsize));
if (entry_p == NULL)
return TABLE_ERROR_ALLOC;
/* add it back to the front of the list */
entry_p->te_data_size = dsize;
entry_p->te_next_p = table_p->ta_buckets[bucket];
table_p->ta_buckets[bucket] = entry_p;
}
/* copy or replace data in storage */
if (dsize > 0) {
if (table_p->ta_data_align == 0)
data_copy_p = ENTRY_DATA_BUF(table_p, entry_p);
else
data_copy_p = entry_data_buf(table_p, entry_p);
if (data_buf != NULL)
memcpy(data_copy_p, data_buf, dsize);
}
else
data_copy_p = NULL;
if (key_buf_p != NULL)
*key_buf_p = ENTRY_KEY_BUF(entry_p);
if (data_buf_p != NULL)
*data_buf_p = data_copy_p;
/* returning from the section where we were overwriting table data */
return TABLE_ERROR_NONE;
}
/*
* It is a new entry.
*/
/* allocate a new entry */
entry_p = (table_entry_t *)
table_p->ta_malloc(table_p->opt_param,
entry_size(table_p, ksize, dsize));
if (entry_p == NULL)
return TABLE_ERROR_ALLOC;
/* copy key into storage */
entry_p->te_key_size = ksize;
key_copy_p = ENTRY_KEY_BUF(entry_p);
memcpy(key_copy_p, key_buf, ksize);
/* copy data in */
entry_p->te_data_size = dsize;
if (dsize > 0) {
if (table_p->ta_data_align == 0)
data_copy_p = ENTRY_DATA_BUF(table_p, entry_p);
else
data_copy_p = entry_data_buf(table_p, entry_p);
if (data_buf != NULL)
memcpy(data_copy_p, data_buf, dsize);
}
else
data_copy_p = NULL;
if (key_buf_p != NULL)
*key_buf_p = key_copy_p;
if (data_buf_p != NULL)
*data_buf_p = data_copy_p;
/* insert into list, no need to append */
entry_p->te_next_p = table_p->ta_buckets[bucket];
table_p->ta_buckets[bucket] = entry_p;
table_p->ta_entry_n++;
/* do we need auto-adjust? */
if (table_p->ta_flags & TABLE_FLAG_AUTO_ADJUST
&& SHOULD_TABLE_GROW(table_p))
return table_adjust(table_p, table_p->ta_entry_n);
return TABLE_ERROR_NONE;
}
/*
* int table_insert
*
* DESCRIPTION:
*
* Exactly the same as table_insert_kd except it does not pass back a
* pointer to the key after they have been inserted into the table
* structure. This is still here for backwards compatibility.
*
* See table_insert_kd for more information.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer into which we will be inserting a
* new key/data pair.
*
* key_buf - Buffer of bytes of the key that we are inserting. If you
* are storing an (int) as the key (for example) then key_buf should
* be a (int *).
*
* key_size - Size of the key_buf buffer. If set to < 0 then the
* library will do a strlen of key_buf and add 1 for the '\0'. If you
* are storing an (int) as the key (for example) then key_size should
* be sizeof(int).
*
* data_buf - Buffer of bytes of the data that we are inserting. If
* it is NULL then the library will allocate space for the data in the
* table without copying in any information. If data_buf is NULL and
* data_size is 0 then the library will associate a NULL data pointer
* with the key. If you are storing a (long) as the data (for
* example) then data_buf should be a (long *).
*
* data_size - Size of the data_buf buffer. If set to < 0 then the
* library will do a strlen of data_buf and add 1 for the '\0'. If
* you are storing an (long) as the key (for example) then key_size
* should be sizeof(long).
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that was allocated in the table. If you are
* storing an (long) as the data (for example) then data_buf_p should
* be (long **) i.e. the address of a (long *).
*
* overwrite - Flag which, if set to 1, will allow the overwriting of
* the data in the table with the new data if the key already exists
* in the table.
*/
int table_insert(table_t * table_p,
const void *key_buf, const int key_size,
const void *data_buf, const int data_size,
void **data_buf_p, const char overwrite_b)
{
return table_insert_kd(table_p, key_buf, key_size, data_buf, data_size,
NULL, data_buf_p, overwrite_b);
}
/*
* int table_retrieve
*
* DESCRIPTION:
*
* This routine looks up a key made up of a buffer of bytes and an
* associated size in the table. If found then it returns the
* associated data information.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer into which we will be searching
* for the key.
*
* key_buf - Buffer of bytes of the key that we are searching for. If
* you are looking for an (int) as the key (for example) then key_buf
* should be a (int *).
*
* key_size - Size of the key_buf buffer. If set to < 0 then the
* library will do a strlen of key_buf and add 1 for the '\0'. If you
* are looking for an (int) as the key (for example) then key_size
* should be sizeof(int).
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that was allocated in the table and that is
* associated with the key. If a (long) was stored as the data (for
* example) then data_buf_p should be (long **) i.e. the address of a
* (long *).
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data stored in the table that is associated with
* the key.
*/
int table_retrieve(table_t * table_p,
const void *key_buf, const int key_size,
void **data_buf_p, int *data_size_p)
{
int bucket;
unsigned int ksize;
table_entry_t *entry_p, **buckets;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (key_buf == NULL)
return TABLE_ERROR_ARG_NULL;
/* find key size */
if (key_size < 0)
ksize = strlen((char *) key_buf) + sizeof(char);
else
ksize = key_size;
/* get the bucket number via a has function */
bucket = hash(key_buf, ksize, 0) % table_p->ta_bucket_n;
/* look for the entry in this bucket, only check keys of the same size */
buckets = table_p->ta_buckets;
for (entry_p = buckets[bucket];
entry_p != NULL;
entry_p = entry_p->te_next_p) {
entry_p = TABLE_POINTER(table_p, table_entry_t *, entry_p);
if (entry_p->te_key_size == ksize
&& memcmp(ENTRY_KEY_BUF(entry_p), key_buf, ksize) == 0)
break;
}
/* not found? */
if (entry_p == NULL)
return TABLE_ERROR_NOT_FOUND;
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
if (table_p->ta_data_align == 0)
*data_buf_p = ENTRY_DATA_BUF(table_p, entry_p);
else
*data_buf_p = entry_data_buf(table_p, entry_p);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
return TABLE_ERROR_NONE;
}
/*
* int table_delete
*
* DESCRIPTION:
*
* This routine looks up a key made up of a buffer of bytes and an
* associated size in the table. If found then it will be removed
* from the table. The associated data can be passed back to the user
* if requested.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* NOTE: this could be an allocation error if the library is to return
* the data to the user.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we will be deleteing
* the key.
*
* key_buf - Buffer of bytes of the key that we are searching for to
* delete. If you are deleting an (int) key (for example) then
* key_buf should be a (int *).
*
* key_size - Size of the key_buf buffer. If set to < 0 then the
* library will do a strlen of key_buf and add 1 for the '\0'. If you
* are deleting an (int) key (for example) then key_size should be
* sizeof(int).
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that was allocated in the table and that was
* associated with the key. If a (long) was stored as the data (for
* example) then data_buf_p should be (long **) i.e. the address of a
* (long *). If a pointer is passed in, the caller is responsible for
* freeing it after use. If data_buf_p is NULL then the library will
* free up the data allocation itself.
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data that was stored in the table and that was
* associated with the key.
*/
int table_delete(table_t * table_p,
const void *key_buf, const int key_size,
void **data_buf_p, int *data_size_p)
{
int bucket;
unsigned int ksize;
unsigned char *data_copy_p;
table_entry_t *entry_p, *last_p;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (key_buf == NULL)
return TABLE_ERROR_ARG_NULL;
/* get the key size */
if (key_size < 0)
ksize = strlen((char *) key_buf) + sizeof(char);
else
ksize = key_size;
/* find our bucket */
bucket = hash(key_buf, ksize, 0) % table_p->ta_bucket_n;
/* look for the entry in this bucket, only check keys of the same size */
for (last_p = NULL, entry_p = table_p->ta_buckets[bucket]; entry_p != NULL;
last_p = entry_p, entry_p = entry_p->te_next_p) {
if (entry_p->te_key_size == ksize
&& memcmp(ENTRY_KEY_BUF(entry_p), key_buf, ksize) == 0)
break;
}
/* did we find it? */
if (entry_p == NULL)
return TABLE_ERROR_NOT_FOUND;
/*
* NOTE: we may want to adjust the linear counters here if the entry
* we are deleting is the one we are pointing on or is ahead of the
* one in the bucket list
*/
/* remove entry from the linked list */
if (last_p == NULL)
table_p->ta_buckets[bucket] = entry_p->te_next_p;
else
last_p->te_next_p = entry_p->te_next_p;
/* free entry */
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
/*
* if we were storing it compacted, we now need to malloc some
* space if the user wants the value after the delete.
*/
*data_buf_p = table_p->ta_malloc(table_p->opt_param,
entry_p->te_data_size);
if (*data_buf_p == NULL)
return TABLE_ERROR_ALLOC;
if (table_p->ta_data_align == 0)
data_copy_p = ENTRY_DATA_BUF(table_p, entry_p);
else
data_copy_p = entry_data_buf(table_p, entry_p);
memcpy(*data_buf_p, data_copy_p, entry_p->te_data_size);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
table_p->ta_free(table_p->opt_param, entry_p);
entry_p = NULL;
table_p->ta_entry_n--;
/* do we need auto-adjust down? */
if ((table_p->ta_flags & TABLE_FLAG_AUTO_ADJUST)
&& (table_p->ta_flags & TABLE_FLAG_ADJUST_DOWN)
&& SHOULD_TABLE_SHRINK(table_p))
return table_adjust(table_p, table_p->ta_entry_n);
return TABLE_ERROR_NONE;
}
/*
* int table_delete_first
*
* DESCRIPTION:
*
* This is like the table_delete routines except it deletes the first
* key/data pair in the table instead of an entry corresponding to a
* particular key. The associated key and data information can be
* passed back to the user if requested. This routines is handy to
* clear out a table.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* NOTE: this could be an allocation error if the library is to return
* the data to the user.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we will be deleteing
* the first key.
*
* key_buf_p - Pointer which, if not NULL, will be set to the address
* of the storage of the first key that was allocated in the table.
* If an (int) was stored as the first key (for example) then
* key_buf_p should be (int **) i.e. the address of a (int *). If a
* pointer is passed in, the caller is responsible for freeing it
* after use. If key_buf_p is NULL then the library will free up the
* key allocation itself.
*
* key_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the key that was stored in the table and that was
* associated with the key.
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that was allocated in the table and that was
* associated with the key. If a (long) was stored as the data (for
* example) then data_buf_p should be (long **) i.e. the address of a
* (long *). If a pointer is passed in, the caller is responsible for
* freeing it after use. If data_buf_p is NULL then the library will
* free up the data allocation itself.
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data that was stored in the table and that was
* associated with the key.
*/
int table_delete_first(table_t * table_p,
void **key_buf_p, int *key_size_p,
void **data_buf_p, int *data_size_p)
{
unsigned char *data_copy_p;
table_entry_t *entry_p;
table_linear_t linear;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
/* take the first entry */
entry_p = first_entry(table_p, &linear);
if (entry_p == NULL)
return TABLE_ERROR_NOT_FOUND;
/*
* NOTE: we may want to adjust the linear counters here if the entry
* we are deleting is the one we are pointing on or is ahead of the
* one in the bucket list
*/
/* remove entry from the linked list */
table_p->ta_buckets[linear.tl_bucket_c] = entry_p->te_next_p;
/* free entry */
if (key_buf_p != NULL) {
if (entry_p->te_key_size == 0)
*key_buf_p = NULL;
else {
/*
* if we were storing it compacted, we now need to malloc some
* space if the user wants the value after the delete.
*/
*key_buf_p = table_p->ta_malloc(table_p->opt_param,
entry_p->te_key_size);
if (*key_buf_p == NULL)
return TABLE_ERROR_ALLOC;
memcpy(*key_buf_p, ENTRY_KEY_BUF(entry_p), entry_p->te_key_size);
}
}
if (key_size_p != NULL)
*key_size_p = entry_p->te_key_size;
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
/*
* if we were storing it compacted, we now need to malloc some
* space if the user wants the value after the delete.
*/
*data_buf_p = table_p->ta_malloc(table_p->opt_param,
entry_p->te_data_size);
if (*data_buf_p == NULL)
return TABLE_ERROR_ALLOC;
if (table_p->ta_data_align == 0)
data_copy_p = ENTRY_DATA_BUF(table_p, entry_p);
else
data_copy_p = entry_data_buf(table_p, entry_p);
memcpy(*data_buf_p, data_copy_p, entry_p->te_data_size);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
table_p->ta_free(table_p->opt_param, entry_p);
table_p->ta_entry_n--;
/* do we need auto-adjust down? */
if ((table_p->ta_flags & TABLE_FLAG_AUTO_ADJUST)
&& (table_p->ta_flags & TABLE_FLAG_ADJUST_DOWN)
&& SHOULD_TABLE_SHRINK(table_p))
return table_adjust(table_p, table_p->ta_entry_n);
return TABLE_ERROR_NONE;
}
/*
* int table_info
*
* DESCRIPTION:
*
* Get some information about a table_p structure.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we are getting
* information.
*
* num_buckets_p - Pointer to an integer which, if not NULL, will
* contain the number of buckets in the table.
*
* num_entries_p - Pointer to an integer which, if not NULL, will
* contain the number of entries stored in the table.
*/
int table_info(table_t * table_p, int *num_buckets_p, int *num_entries_p)
{
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (num_buckets_p != NULL)
*num_buckets_p = table_p->ta_bucket_n;
if (num_entries_p != NULL)
*num_entries_p = table_p->ta_entry_n;
return TABLE_ERROR_NONE;
}
/*
* int table_adjust
*
* DESCRIPTION:
*
* Set the number of buckets in a table to a certain value.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer of which we are adjusting.
*
* bucket_n - Number buckets to adjust the table to. Set to 0 to
* adjust the table to its number of entries.
*/
int table_adjust(table_t * table_p, const int bucket_n)
{
table_entry_t *entry_p, *next_p;
table_entry_t **buckets, **bucket_p, **bounds_p;
int bucket;
unsigned int buck_n;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
/*
* NOTE: we walk through the entries and rehash them. If we stored
* the hash value as a full int in the table-entry, all we would
* have to do is remod it.
*/
/* normalize to the number of entries */
if (bucket_n == 0)
buck_n = table_p->ta_entry_n;
else
buck_n = bucket_n;
/* we must have at least 1 bucket */
if (buck_n == 0)
buck_n = 1;
/* make sure we have somethign to do */
if (buck_n <= table_p->ta_bucket_n)
return TABLE_ERROR_NONE;
/* allocate a new bucket list */
buckets = (table_entry_t **)
table_p->ta_calloc(table_p->opt_param,
buck_n, sizeof(table_entry_t *));
if (table_p->ta_buckets == NULL)
return TABLE_ERROR_ALLOC;
/*
* run through each of the items in the current table and rehash
* them into the newest bucket sizes
*/
bounds_p = table_p->ta_buckets + table_p->ta_bucket_n;
for (bucket_p = table_p->ta_buckets; bucket_p < bounds_p; bucket_p++) {
for (entry_p = *bucket_p; entry_p != NULL; entry_p = next_p) {
/* hash the old data into the new table size */
bucket = hash(ENTRY_KEY_BUF(entry_p), entry_p->te_key_size, 0) % buck_n;
/* record the next one now since we overwrite next below */
next_p = entry_p->te_next_p;
/* insert into new list, no need to append */
entry_p->te_next_p = buckets[bucket];
buckets[bucket] = entry_p;
/*
* NOTE: we may want to adjust the bucket_c linear entry here to
* keep it current
*/
}
/* remove the old table pointers as we go by */
*bucket_p = NULL;
}
/* replace the table buckets with the new ones */
table_p->ta_free(table_p->opt_param, table_p->ta_buckets);
table_p->ta_buckets = buckets;
table_p->ta_bucket_n = buck_n;
return TABLE_ERROR_NONE;
}
/*
* const char *table_strerror
*
* DESCRIPTION:
*
* Return the corresponding string for the error number.
*
* RETURNS:
*
* Success - String equivalient of the error.
*
* Failure - String "invalid error code"
*
* ARGUMENTS:
*
* error - Error number that we are converting.
*/
const char *table_strerror(const int error)
{
error_str_t *err_p;
for (err_p = errors; err_p->es_error != 0; err_p++) {
if (err_p->es_error == error)
return err_p->es_string;
}
return INVALID_ERROR;
}
/*
* int table_type_size
*
* DESCRIPTION:
*
* Return the size of the internal table type.
*
* RETURNS:
*
* The size of the table_t type.
*
* ARGUMENTS:
*
* None.
*/
int table_type_size(void)
{
return sizeof(table_t);
}
/************************* linear access routines ****************************/
/*
* int table_first
*
* DESCRIPTION:
*
* Find first element in a table and pass back information about the
* key/data pair. If any of the key/data pointers are NULL then they
* are ignored.
*
* NOTE: This function is not reentrant. More than one thread cannot
* be doing a first and next on the same table at the same time. Use
* the table_first_r version below for this.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we are getting the
* first element.
*
* key_buf_p - Pointer which, if not NULL, will be set to the address
* of the storage of the first key that is allocated in the table. If
* an (int) is stored as the first key (for example) then key_buf_p
* should be (int **) i.e. the address of a (int *).
*
* key_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the key that is stored in the table and that is
* associated with the first key.
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that is allocated in the table and that is
* associated with the first key. If a (long) is stored as the data
* (for example) then data_buf_p should be (long **) i.e. the address
* of a (long *).
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data that is stored in the table and that is
* associated with the first key.
*/
int table_first(table_t * table_p,
void **key_buf_p, int *key_size_p,
void **data_buf_p, int *data_size_p)
{
table_entry_t *entry_p;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
/* initialize our linear magic number */
table_p->ta_linear.tl_magic = LINEAR_MAGIC;
entry_p = first_entry(table_p, &table_p->ta_linear);
if (entry_p == NULL)
return TABLE_ERROR_NOT_FOUND;
if (key_buf_p != NULL)
*key_buf_p = ENTRY_KEY_BUF(entry_p);
if (key_size_p != NULL)
*key_size_p = entry_p->te_key_size;
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
if (table_p->ta_data_align == 0)
*data_buf_p = ENTRY_DATA_BUF(table_p, entry_p);
else
*data_buf_p = entry_data_buf(table_p, entry_p);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
return TABLE_ERROR_NONE;
}
/*
* int table_next
*
* DESCRIPTION:
*
* Find the next element in a table and pass back information about
* the key/data pair. If any of the key/data pointers are NULL then
* they are ignored.
*
* NOTE: This function is not reentrant. More than one thread cannot
* be doing a first and next on the same table at the same time. Use
* the table_next_r version below for this.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we are getting the
* next element.
*
* key_buf_p - Pointer which, if not NULL, will be set to the address
* of the storage of the next key that is allocated in the table. If
* an (int) is stored as the next key (for example) then key_buf_p
* should be (int **) i.e. the address of a (int *).
*
* key_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the key that is stored in the table and that is
* associated with the next key.
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that is allocated in the table and that is
* associated with the next key. If a (long) is stored as the data
* (for example) then data_buf_p should be (long **) i.e. the address
* of a (long *).
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data that is stored in the table and that is
* associated with the next key.
*/
int table_next(table_t * table_p,
void **key_buf_p, int *key_size_p,
void **data_buf_p, int *data_size_p)
{
table_entry_t *entry_p;
int error;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (table_p->ta_linear.tl_magic != LINEAR_MAGIC)
return TABLE_ERROR_LINEAR;
/* move to the next entry */
entry_p = next_entry(table_p, &table_p->ta_linear, &error);
if (entry_p == NULL)
return error;
if (key_buf_p != NULL)
*key_buf_p = ENTRY_KEY_BUF(entry_p);
if (key_size_p != NULL)
*key_size_p = entry_p->te_key_size;
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
if (table_p->ta_data_align == 0)
*data_buf_p = ENTRY_DATA_BUF(table_p, entry_p);
else
*data_buf_p = entry_data_buf(table_p, entry_p);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
return TABLE_ERROR_NONE;
}
/*
* int table_this
*
* DESCRIPTION:
*
* Find the current element in a table and pass back information about
* the key/data pair. If any of the key/data pointers are NULL then
* they are ignored.
*
* NOTE: This function is not reentrant. Use the table_current_r
* version below.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we are getting the
* current element.
*
* key_buf_p - Pointer which, if not NULL, will be set to the address
* of the storage of the current key that is allocated in the table.
* If an (int) is stored as the current key (for example) then
* key_buf_p should be (int **) i.e. the address of a (int *).
*
* key_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the key that is stored in the table and that is
* associated with the current key.
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that is allocated in the table and that is
* associated with the current key. If a (long) is stored as the data
* (for example) then data_buf_p should be (long **) i.e. the address
* of a (long *).
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data that is stored in the table and that is
* associated with the current key.
*/
int table_this(table_t * table_p,
void **key_buf_p, int *key_size_p,
void **data_buf_p, int *data_size_p)
{
table_entry_t *entry_p = NULL;
int entry_c;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (table_p->ta_linear.tl_magic != LINEAR_MAGIC)
return TABLE_ERROR_LINEAR;
/* if we removed an item that shorted the bucket list, we may get this */
if (table_p->ta_linear.tl_bucket_c >= table_p->ta_bucket_n) {
/*
* NOTE: this might happen if we delete an item which shortens the
* table bucket numbers.
*/
return TABLE_ERROR_NOT_FOUND;
}
/* find the entry which is the nth in the list */
entry_p = table_p->ta_buckets[table_p->ta_linear.tl_bucket_c];
/* NOTE: we swap the order here to be more efficient */
for (entry_c = table_p->ta_linear.tl_entry_c; entry_c > 0; entry_c--) {
/* did we reach the end of the list? */
if (entry_p == NULL)
break;
entry_p = TABLE_POINTER(table_p, table_entry_t *, entry_p)->te_next_p;
}
/* is this a NOT_FOUND or a LINEAR error */
if (entry_p == NULL)
return TABLE_ERROR_NOT_FOUND;
if (key_buf_p != NULL)
*key_buf_p = ENTRY_KEY_BUF(entry_p);
if (key_size_p != NULL)
*key_size_p = entry_p->te_key_size;
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
if (table_p->ta_data_align == 0)
*data_buf_p = ENTRY_DATA_BUF(table_p, entry_p);
else
*data_buf_p = entry_data_buf(table_p, entry_p);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
return TABLE_ERROR_NONE;
}
/*
* int table_first_r
*
* DESCRIPTION:
*
* Reetrant version of the table_first routine above. Find first
* element in a table and pass back information about the key/data
* pair. If any of the key/data pointers are NULL then they are
* ignored.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we are getting the
* first element.
*
* linear_p - Pointer to a table linear structure which is initialized
* here. The same pointer should then be passed to table_next_r
* below.
*
* key_buf_p - Pointer which, if not NULL, will be set to the address
* of the storage of the first key that is allocated in the table. If
* an (int) is stored as the first key (for example) then key_buf_p
* should be (int **) i.e. the address of a (int *).
*
* key_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the key that is stored in the table and that is
* associated with the first key.
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that is allocated in the table and that is
* associated with the first key. If a (long) is stored as the data
* (for example) then data_buf_p should be (long **) i.e. the address
* of a (long *).
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data that is stored in the table and that is
* associated with the first key.
*/
int table_first_r(table_t * table_p, table_linear_t * linear_p,
void **key_buf_p, int *key_size_p,
void **data_buf_p, int *data_size_p)
{
table_entry_t *entry_p;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (linear_p == NULL)
return TABLE_ERROR_ARG_NULL;
/* initialize our linear magic number */
linear_p->tl_magic = LINEAR_MAGIC;
entry_p = first_entry(table_p, linear_p);
if (entry_p == NULL)
return TABLE_ERROR_NOT_FOUND;
if (key_buf_p != NULL)
*key_buf_p = ENTRY_KEY_BUF(entry_p);
if (key_size_p != NULL)
*key_size_p = entry_p->te_key_size;
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
if (table_p->ta_data_align == 0)
*data_buf_p = ENTRY_DATA_BUF(table_p, entry_p);
else
*data_buf_p = entry_data_buf(table_p, entry_p);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
return TABLE_ERROR_NONE;
}
/*
* int table_next_r
*
* DESCRIPTION:
*
* Reetrant version of the table_next routine above. Find next
* element in a table and pass back information about the key/data
* pair. If any of the key/data pointers are NULL then they are
* ignored.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we are getting the
* next element.
*
* linear_p - Pointer to a table linear structure which is incremented
* here. The same pointer must have been passed to table_first_r
* first so that it can be initialized.
*
* key_buf_p - Pointer which, if not NULL, will be set to the address
* of the storage of the next key that is allocated in the table. If
* an (int) is stored as the next key (for example) then key_buf_p
* should be (int **) i.e. the address of a (int *).
*
* key_size_p - Pointer to an integer which, if not NULL will be set
* to the size of the key that is stored in the table and that is
* associated with the next key.
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that is allocated in the table and that is
* associated with the next key. If a (long) is stored as the data
* (for example) then data_buf_p should be (long **) i.e. the address
* of a (long *).
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data that is stored in the table and that is
* associated with the next key.
*/
int table_next_r(table_t * table_p, table_linear_t * linear_p,
void **key_buf_p, int *key_size_p,
void **data_buf_p, int *data_size_p)
{
table_entry_t *entry_p;
int error;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (linear_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (linear_p->tl_magic != LINEAR_MAGIC)
return TABLE_ERROR_LINEAR;
/* move to the next entry */
entry_p = next_entry(table_p, linear_p, &error);
if (entry_p == NULL)
return error;
if (key_buf_p != NULL)
*key_buf_p = ENTRY_KEY_BUF(entry_p);
if (key_size_p != NULL)
*key_size_p = entry_p->te_key_size;
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
if (table_p->ta_data_align == 0)
*data_buf_p = ENTRY_DATA_BUF(table_p, entry_p);
else
*data_buf_p = entry_data_buf(table_p, entry_p);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
return TABLE_ERROR_NONE;
}
/*
* int table_this_r
*
* DESCRIPTION:
*
* Reetrant version of the table_this routine above. Find current
* element in a table and pass back information about the key/data
* pair. If any of the key/data pointers are NULL then they are
* ignored.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we are getting the
* current element.
*
* linear_p - Pointer to a table linear structure which is accessed
* here. The same pointer must have been passed to table_first_r
* first so that it can be initialized.
*
* key_buf_p - Pointer which, if not NULL, will be set to the address
* of the storage of the current key that is allocated in the table.
* If an (int) is stored as the current key (for example) then
* key_buf_p should be (int **) i.e. the address of a (int *).
*
* key_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the key that is stored in the table and that is
* associated with the current key.
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage that is allocated in the table and that is
* associated with the current key. If a (long) is stored as the data
* (for example) then data_buf_p should be (long **) i.e. the address
* of a (long *).
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data that is stored in the table and that is
* associated with the current key.
*/
int table_this_r(table_t * table_p, table_linear_t * linear_p,
void **key_buf_p, int *key_size_p,
void **data_buf_p, int *data_size_p)
{
table_entry_t *entry_p;
int entry_c;
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (linear_p->tl_magic != LINEAR_MAGIC)
return TABLE_ERROR_LINEAR;
/* if we removed an item that shorted the bucket list, we may get this */
if (linear_p->tl_bucket_c >= table_p->ta_bucket_n) {
/*
* NOTE: this might happen if we delete an item which shortens the
* table bucket numbers.
*/
return TABLE_ERROR_NOT_FOUND;
}
/* find the entry which is the nth in the list */
for (entry_c = linear_p->tl_entry_c,
entry_p = table_p->ta_buckets[linear_p->tl_bucket_c];
entry_p != NULL && entry_c > 0;
entry_c--, entry_p = TABLE_POINTER(table_p, table_entry_t *,
entry_p)->te_next_p) {
}
if (entry_p == NULL)
return TABLE_ERROR_NOT_FOUND;
if (key_buf_p != NULL)
*key_buf_p = ENTRY_KEY_BUF(entry_p);
if (key_size_p != NULL)
*key_size_p = entry_p->te_key_size;
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
if (table_p->ta_data_align == 0)
*data_buf_p = ENTRY_DATA_BUF(table_p, entry_p);
else
*data_buf_p = entry_data_buf(table_p, entry_p);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
return TABLE_ERROR_NONE;
}
/******************************** table order ********************************/
/*
* table_entry_t *table_order
*
* DESCRIPTION:
*
* Order a table by building an array of table entry pointers and then
* sorting this array using the qsort function. To retrieve the
* sorted entries, you can then use the table_entry routine to access
* each entry in order.
*
* NOTE: This routine is now thread safe in that two table_order calls
* can now happen at the same time, even on the same table.
*
* RETURNS:
*
* An allocated list of entry pointers which must be freed later.
* Returns null on error.
*
* ARGUMENTS:
*
* table_p - Pointer to the table that we are ordering.
*
* compare - Comparison function defined by the user. Its definition
* is at the top of the table.h file. If this is NULL then it will
* order the table my memcmp-ing the keys.
*
* num_entries_p - Pointer to an integer which, if not NULL, will
* contain the number of entries in the returned entry pointer array.
*
* error_p - Pointer to an integer which, if not NULL, will contain a
* table error code.
*/
table_entry_t **table_order(table_t * table_p, table_compare_t compare,
int *num_entries_p, int *error_p)
{
table_entry_t *entry_p, **entries, **entries_p;
table_linear_t linear;
compare_t comp_func;
int error;
if (table_p == NULL) {
if (error_p != NULL)
*error_p = TABLE_ERROR_ARG_NULL;
return NULL;
}
if (table_p->ta_magic != TABLE_MAGIC) {
if (error_p != NULL)
*error_p = TABLE_ERROR_PNT;
return NULL;
}
/* there must be at least 1 element in the table for this to work */
if (table_p->ta_entry_n == 0) {
if (error_p != NULL)
*error_p = TABLE_ERROR_EMPTY;
return NULL;
}
entries = (table_entry_t **)
table_p->ta_malloc(table_p->opt_param,
table_p->ta_entry_n *sizeof(table_entry_t *));
if (entries == NULL) {
if (error_p != NULL)
*error_p = TABLE_ERROR_ALLOC;
return NULL;
}
/* get a pointer to all entries */
entry_p = first_entry(table_p, &linear);
if (entry_p == NULL) {
if (error_p != NULL)
*error_p = TABLE_ERROR_NOT_FOUND;
return NULL;
}
/* add all of the entries to the array */
for (entries_p = entries;
entry_p != NULL;
entry_p = next_entry(table_p, &linear, &error))
*entries_p++ = entry_p;
if (error != TABLE_ERROR_NOT_FOUND) {
if (error_p != NULL)
*error_p = error;
return NULL;
}
if (compare == NULL) {
/* this is regardless of the alignment */
comp_func = local_compare;
}
else if (table_p->ta_data_align == 0)
comp_func = external_compare;
else
comp_func = external_compare_align;
/* now qsort the entire entries array from first to last element */
split(entries, entries + table_p->ta_entry_n - 1, comp_func, compare,
table_p);
if (num_entries_p != NULL)
*num_entries_p = table_p->ta_entry_n;
if (error_p != NULL)
*error_p = TABLE_ERROR_NONE;
return entries;
}
/*
* int table_entry
*
* DESCRIPTION:
*
* Get information about an element. The element is one from the
* array returned by the table_order function. If any of the key/data
* pointers are NULL then they are ignored.
*
* RETURNS:
*
* Success - TABLE_ERROR_NONE
*
* Failure - Table error code.
*
* ARGUMENTS:
*
* table_p - Table structure pointer from which we are getting the
* element.
*
* entry_p - Pointer to a table entry from the array returned by the
* table_order function.
*
* key_buf_p - Pointer which, if not NULL, will be set to the address
* of the storage of this entry that is allocated in the table. If an
* (int) is stored as this entry (for example) then key_buf_p should
* be (int **) i.e. the address of a (int *).
*
* key_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the key that is stored in the table.
*
* data_buf_p - Pointer which, if not NULL, will be set to the address
* of the data storage of this entry that is allocated in the table.
* If a (long) is stored as this entry data (for example) then
* data_buf_p should be (long **) i.e. the address of a (long *).
*
* data_size_p - Pointer to an integer which, if not NULL, will be set
* to the size of the data that is stored in the table.
*/
int table_entry_info(table_t * table_p, table_entry_t * entry_p,
void **key_buf_p, int *key_size_p,
void **data_buf_p, int *data_size_p)
{
if (table_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (table_p->ta_magic != TABLE_MAGIC)
return TABLE_ERROR_PNT;
if (entry_p == NULL)
return TABLE_ERROR_ARG_NULL;
if (key_buf_p != NULL)
*key_buf_p = ENTRY_KEY_BUF(entry_p);
if (key_size_p != NULL)
*key_size_p = entry_p->te_key_size;
if (data_buf_p != NULL) {
if (entry_p->te_data_size == 0)
*data_buf_p = NULL;
else {
if (table_p->ta_data_align == 0)
*data_buf_p = ENTRY_DATA_BUF(table_p, entry_p);
else
*data_buf_p = entry_data_buf(table_p, entry_p);
}
}
if (data_size_p != NULL)
*data_size_p = entry_p->te_data_size;
return TABLE_ERROR_NONE;
}