| /* |
| * string.c: routines to manipulate counted-length strings |
| * (svn_stringbuf_t and svn_string_t) and C strings. |
| * |
| * |
| * ==================================================================== |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * ==================================================================== |
| */ |
| |
| |
| |
| #include <apr.h> |
| #include <assert.h> |
| |
| #include <string.h> /* for memcpy(), memcmp(), strlen() */ |
| #include <apr_fnmatch.h> |
| #include "svn_string.h" /* loads "svn_types.h" and <apr_pools.h> */ |
| #include "svn_ctype.h" |
| #include "private/svn_dep_compat.h" |
| #include "private/svn_string_private.h" |
| |
| #include "svn_private_config.h" |
| |
| |
| |
| /* Allocate the space for a memory buffer from POOL. |
| * Return a pointer to the new buffer in *DATA and its size in *SIZE. |
| * The buffer size will be at least MINIMUM_SIZE. |
| * |
| * N.B.: The stringbuf creation functions use this, but since stringbufs |
| * always consume at least 1 byte for the NUL terminator, the |
| * resulting data pointers will never be NULL. |
| */ |
| static APR_INLINE void |
| membuf_create(void **data, apr_size_t *size, |
| apr_size_t minimum_size, apr_pool_t *pool) |
| { |
| /* apr_palloc will allocate multiples of 8. |
| * Thus, we would waste some of that memory if we stuck to the |
| * smaller size. Note that this is safe even if apr_palloc would |
| * use some other alignment or none at all. */ |
| minimum_size = APR_ALIGN_DEFAULT(minimum_size); |
| *data = apr_palloc(pool, minimum_size); |
| *size = minimum_size; |
| } |
| |
| /* Ensure that the size of a given memory buffer is at least MINIMUM_SIZE |
| * bytes. If *SIZE is already greater than or equal to MINIMUM_SIZE, |
| * this function does nothing. |
| * |
| * If *SIZE is 0, the allocated buffer size will be MINIMUM_SIZE |
| * rounded up to the nearest APR alignment boundary. Otherwse, *SIZE |
| * will be multiplied by a power of two such that the result is |
| * greater or equal to MINIMUM_SIZE. The pointer to the new buffer |
| * will be returned in *DATA, and its size in *SIZE. |
| */ |
| static APR_INLINE void |
| membuf_ensure(void **data, apr_size_t *size, |
| apr_size_t minimum_size, apr_pool_t *pool) |
| { |
| if (minimum_size > *size) |
| { |
| apr_size_t new_size = *size; |
| |
| if (new_size == 0) |
| new_size = minimum_size; |
| else |
| while (new_size < minimum_size) |
| { |
| const apr_size_t prev_size = new_size; |
| new_size *= 2; |
| |
| /* check for apr_size_t overflow */ |
| if (prev_size > new_size) |
| { |
| new_size = minimum_size; |
| break; |
| } |
| } |
| |
| membuf_create(data, size, new_size, pool); |
| } |
| } |
| |
| void |
| svn_membuf__create(svn_membuf_t *membuf, apr_size_t size, apr_pool_t *pool) |
| { |
| membuf_create(&membuf->data, &membuf->size, size, pool); |
| membuf->pool = pool; |
| } |
| |
| void |
| svn_membuf__ensure(svn_membuf_t *membuf, apr_size_t size) |
| { |
| membuf_ensure(&membuf->data, &membuf->size, size, membuf->pool); |
| } |
| |
| void |
| svn_membuf__resize(svn_membuf_t *membuf, apr_size_t size) |
| { |
| const void *const old_data = membuf->data; |
| const apr_size_t old_size = membuf->size; |
| |
| membuf_ensure(&membuf->data, &membuf->size, size, membuf->pool); |
| |
| /* If we re-allocated MEMBUF->DATA, it cannot be NULL. |
| * Statically initialized membuffers (OLD_DATA) may be NULL, though. */ |
| if (old_data && old_data != membuf->data) |
| memcpy(membuf->data, old_data, old_size); |
| } |
| |
| /* Always provide an out-of-line implementation of svn_membuf__zero */ |
| #undef svn_membuf__zero |
| void |
| svn_membuf__zero(svn_membuf_t *membuf) |
| { |
| SVN_MEMBUF__ZERO(membuf); |
| } |
| |
| /* Always provide an out-of-line implementation of svn_membuf__nzero */ |
| #undef svn_membuf__nzero |
| void |
| svn_membuf__nzero(svn_membuf_t *membuf, apr_size_t size) |
| { |
| SVN_MEMBUF__NZERO(membuf, size); |
| } |
| |
| static APR_INLINE svn_boolean_t |
| string_compare(const char *str1, |
| const char *str2, |
| apr_size_t len1, |
| apr_size_t len2) |
| { |
| /* easy way out :) */ |
| if (len1 != len2) |
| return FALSE; |
| |
| /* now the strings must have identical lengths */ |
| |
| if ((memcmp(str1, str2, len1)) == 0) |
| return TRUE; |
| else |
| return FALSE; |
| } |
| |
| static APR_INLINE apr_size_t |
| string_first_non_whitespace(const char *str, apr_size_t len) |
| { |
| apr_size_t i; |
| |
| for (i = 0; i < len; i++) |
| { |
| if (! svn_ctype_isspace(str[i])) |
| return i; |
| } |
| |
| /* if we get here, then the string must be entirely whitespace */ |
| return len; |
| } |
| |
| static APR_INLINE apr_size_t |
| find_char_backward(const char *str, apr_size_t len, char ch) |
| { |
| apr_size_t i = len; |
| |
| while (i != 0) |
| { |
| if (str[--i] == ch) |
| return i; |
| } |
| |
| /* char was not found, return len */ |
| return len; |
| } |
| |
| |
| /* svn_string functions */ |
| |
| /* Return a new svn_string_t object, allocated in POOL, initialized with |
| * DATA and SIZE. Do not copy the contents of DATA, just store the pointer. |
| * SIZE is the length in bytes of DATA, excluding the required NUL |
| * terminator. */ |
| static svn_string_t * |
| create_string(const char *data, apr_size_t size, |
| apr_pool_t *pool) |
| { |
| svn_string_t *new_string; |
| |
| new_string = apr_palloc(pool, sizeof(*new_string)); |
| |
| new_string->data = data; |
| new_string->len = size; |
| |
| return new_string; |
| } |
| |
| /* A data buffer for a zero-length string (just a null terminator). Many |
| * svn_string_t instances may share this same buffer. */ |
| static const char empty_buffer[1] = {0}; |
| |
| svn_string_t * |
| svn_string_create_empty(apr_pool_t *pool) |
| { |
| svn_string_t *new_string = apr_palloc(pool, sizeof(*new_string)); |
| new_string->data = empty_buffer; |
| new_string->len = 0; |
| |
| return new_string; |
| } |
| |
| |
| svn_string_t * |
| svn_string_ncreate(const char *bytes, apr_size_t size, apr_pool_t *pool) |
| { |
| void *mem; |
| char *data; |
| svn_string_t *new_string; |
| |
| /* Allocate memory for svn_string_t and data in one chunk. */ |
| mem = apr_palloc(pool, sizeof(*new_string) + size + 1); |
| data = (char*)mem + sizeof(*new_string); |
| |
| new_string = mem; |
| new_string->data = data; |
| new_string->len = size; |
| |
| /* If SIZE is 0, NULL is valid for BYTES. */ |
| if (size) |
| memcpy(data, bytes, size); |
| |
| /* Null termination is the convention -- even if we suspect the data |
| to be binary, it's not up to us to decide, it's the caller's |
| call. Heck, that's why they call it the caller! */ |
| data[size] = '\0'; |
| |
| return new_string; |
| } |
| |
| |
| svn_string_t * |
| svn_string_create(const char *cstring, apr_pool_t *pool) |
| { |
| return svn_string_ncreate(cstring, strlen(cstring), pool); |
| } |
| |
| |
| svn_string_t * |
| svn_string_create_from_buf(const svn_stringbuf_t *strbuf, apr_pool_t *pool) |
| { |
| return svn_string_ncreate(strbuf->data, strbuf->len, pool); |
| } |
| |
| |
| svn_string_t * |
| svn_string_createv(apr_pool_t *pool, const char *fmt, va_list ap) |
| { |
| char *data = apr_pvsprintf(pool, fmt, ap); |
| |
| /* wrap an svn_string_t around the new data */ |
| return create_string(data, strlen(data), pool); |
| } |
| |
| |
| svn_string_t * |
| svn_string_createf(apr_pool_t *pool, const char *fmt, ...) |
| { |
| svn_string_t *str; |
| |
| va_list ap; |
| va_start(ap, fmt); |
| str = svn_string_createv(pool, fmt, ap); |
| va_end(ap); |
| |
| return str; |
| } |
| |
| |
| svn_boolean_t |
| svn_string_isempty(const svn_string_t *str) |
| { |
| return (str->len == 0); |
| } |
| |
| |
| svn_string_t * |
| svn_string_dup(const svn_string_t *original_string, apr_pool_t *pool) |
| { |
| return (original_string ? svn_string_ncreate(original_string->data, |
| original_string->len, pool) |
| : NULL); |
| } |
| |
| |
| |
| svn_boolean_t |
| svn_string_compare(const svn_string_t *str1, const svn_string_t *str2) |
| { |
| return |
| string_compare(str1->data, str2->data, str1->len, str2->len); |
| } |
| |
| |
| |
| apr_size_t |
| svn_string_first_non_whitespace(const svn_string_t *str) |
| { |
| return |
| string_first_non_whitespace(str->data, str->len); |
| } |
| |
| |
| apr_size_t |
| svn_string_find_char_backward(const svn_string_t *str, char ch) |
| { |
| return find_char_backward(str->data, str->len, ch); |
| } |
| |
| svn_string_t * |
| svn_stringbuf__morph_into_string(svn_stringbuf_t *strbuf) |
| { |
| /* In debug mode, detect attempts to modify the original STRBUF object. |
| */ |
| #ifdef SVN_DEBUG |
| strbuf->pool = NULL; |
| strbuf->blocksize = strbuf->len + 1; |
| #endif |
| |
| /* Both, svn_string_t and svn_stringbuf_t are public API structures |
| * since the svn epoch. Thus, we can rely on their precise layout not |
| * to change. |
| * |
| * It just so happens that svn_string_t is structurally equivalent |
| * to the (data, len) sub-set of svn_stringbuf_t. There is also no |
| * difference in alignment and padding. So, we can just re-interpret |
| * that part of STRBUF as a svn_string_t. |
| * |
| * However, since svn_string_t does not know about the blocksize |
| * member in svn_stringbuf_t, any attempt to re-size the returned |
| * svn_string_t might invalidate the STRBUF struct. Hence, we consider |
| * the source STRBUF "consumed". |
| * |
| * Modifying the string character content is fine, though. |
| */ |
| return (svn_string_t *)&strbuf->data; |
| } |
| |
| |
| |
| /* svn_stringbuf functions */ |
| |
| svn_stringbuf_t * |
| svn_stringbuf_create_empty(apr_pool_t *pool) |
| { |
| return svn_stringbuf_create_ensure(0, pool); |
| } |
| |
| svn_stringbuf_t * |
| svn_stringbuf_create_ensure(apr_size_t blocksize, apr_pool_t *pool) |
| { |
| void *mem; |
| svn_stringbuf_t *new_string; |
| |
| ++blocksize; /* + space for '\0' */ |
| |
| /* Allocate memory for svn_string_t and data in one chunk. */ |
| membuf_create(&mem, &blocksize, blocksize + sizeof(*new_string), pool); |
| |
| /* Initialize header and string */ |
| new_string = mem; |
| new_string->data = (char*)mem + sizeof(*new_string); |
| new_string->data[0] = '\0'; |
| new_string->len = 0; |
| new_string->blocksize = blocksize - sizeof(*new_string); |
| new_string->pool = pool; |
| |
| return new_string; |
| } |
| |
| svn_stringbuf_t * |
| svn_stringbuf_ncreate(const char *bytes, apr_size_t size, apr_pool_t *pool) |
| { |
| svn_stringbuf_t *strbuf = svn_stringbuf_create_ensure(size, pool); |
| |
| /* If SIZE is 0, NULL is valid for BYTES. */ |
| if (size) |
| memcpy(strbuf->data, bytes, size); |
| |
| /* Null termination is the convention -- even if we suspect the data |
| to be binary, it's not up to us to decide, it's the caller's |
| call. Heck, that's why they call it the caller! */ |
| strbuf->data[size] = '\0'; |
| strbuf->len = size; |
| |
| return strbuf; |
| } |
| |
| |
| svn_stringbuf_t * |
| svn_stringbuf_create(const char *cstring, apr_pool_t *pool) |
| { |
| return svn_stringbuf_ncreate(cstring, strlen(cstring), pool); |
| } |
| |
| |
| svn_stringbuf_t * |
| svn_stringbuf_create_from_string(const svn_string_t *str, apr_pool_t *pool) |
| { |
| return svn_stringbuf_ncreate(str->data, str->len, pool); |
| } |
| |
| svn_stringbuf_t * |
| svn_stringbuf_create_wrap(char *str, apr_pool_t *pool) |
| { |
| svn_stringbuf_t *result = apr_palloc(pool, sizeof(*result)); |
| result->pool = pool; |
| result->data = str; |
| result->len = strlen(str); |
| result->blocksize = result->len + 1; |
| |
| return result; |
| } |
| |
| svn_stringbuf_t * |
| svn_stringbuf_createv(apr_pool_t *pool, const char *fmt, va_list ap) |
| { |
| char *data = apr_pvsprintf(pool, fmt, ap); |
| apr_size_t size = strlen(data); |
| svn_stringbuf_t *new_string; |
| |
| new_string = apr_palloc(pool, sizeof(*new_string)); |
| new_string->data = data; |
| new_string->len = size; |
| new_string->blocksize = size + 1; |
| new_string->pool = pool; |
| |
| return new_string; |
| } |
| |
| |
| svn_stringbuf_t * |
| svn_stringbuf_createf(apr_pool_t *pool, const char *fmt, ...) |
| { |
| svn_stringbuf_t *str; |
| |
| va_list ap; |
| va_start(ap, fmt); |
| str = svn_stringbuf_createv(pool, fmt, ap); |
| va_end(ap); |
| |
| return str; |
| } |
| |
| |
| void |
| svn_stringbuf_fillchar(svn_stringbuf_t *str, unsigned char c) |
| { |
| memset(str->data, c, str->len); |
| } |
| |
| |
| void |
| svn_stringbuf_set(svn_stringbuf_t *str, const char *value) |
| { |
| apr_size_t amt = strlen(value); |
| |
| membuf_ensure((void**) &str->data, &str->blocksize, amt + 1, str->pool); |
| memcpy(str->data, value, amt + 1); |
| str->len = amt; |
| } |
| |
| void |
| svn_stringbuf_setempty(svn_stringbuf_t *str) |
| { |
| str->data[0] = '\0'; |
| str->len = 0; |
| } |
| |
| |
| void |
| svn_stringbuf_chop(svn_stringbuf_t *str, apr_size_t nbytes) |
| { |
| if (nbytes > str->len) |
| str->len = 0; |
| else |
| str->len -= nbytes; |
| |
| str->data[str->len] = '\0'; |
| } |
| |
| void |
| svn_stringbuf_leftchop(svn_stringbuf_t *str, apr_size_t nbytes) |
| { |
| if (str->len == 0) |
| return; |
| |
| if (nbytes >= str->len) |
| { |
| str->len = 0; |
| *str->data = '\0'; |
| } |
| else |
| { |
| /* Note: This will irretrievably waste nbytes of space in the |
| stringbuf's pool, but unlike the alternative of memmoving the |
| data, it's a constant-time operation. */ |
| str->data += nbytes; |
| str->len -= nbytes; |
| str->blocksize -= nbytes; |
| } |
| } |
| |
| svn_boolean_t |
| svn_stringbuf_isempty(const svn_stringbuf_t *str) |
| { |
| return (str->len == 0); |
| } |
| |
| |
| void |
| svn_stringbuf_ensure(svn_stringbuf_t *str, apr_size_t minimum_size) |
| { |
| void *mem = NULL; |
| ++minimum_size; /* + space for '\0' */ |
| |
| membuf_ensure(&mem, &str->blocksize, minimum_size, str->pool); |
| if (mem && mem != str->data) |
| { |
| if (str->data) |
| memcpy(mem, str->data, str->len + 1); |
| str->data = mem; |
| } |
| } |
| |
| |
| /* WARNING - Optimized code ahead! |
| * This function has been hand-tuned for performance. Please read |
| * the comments below before modifying the code. |
| */ |
| void |
| svn_stringbuf_appendbyte(svn_stringbuf_t *str, char byte) |
| { |
| char *dest; |
| apr_size_t old_len = str->len; |
| |
| /* In most cases, there will be pre-allocated memory left |
| * to just write the new byte at the end of the used section |
| * and terminate the string properly. |
| */ |
| if (str->blocksize > old_len + 1) |
| { |
| /* The following read does not depend this write, so we |
| * can issue the write first to minimize register pressure: |
| * The value of old_len+1 is no longer needed; on most processors, |
| * dest[old_len+1] will be calculated implicitly as part of |
| * the addressing scheme. |
| */ |
| str->len = old_len+1; |
| |
| /* Since the compiler cannot be sure that *src->data and *src |
| * don't overlap, we read src->data *once* before writing |
| * to *src->data. Replacing dest with str->data would force |
| * the compiler to read it again after the first byte. |
| */ |
| dest = str->data; |
| |
| /* If not already available in a register as per ABI, load |
| * "byte" into the register (e.g. the one freed from old_len+1), |
| * then write it to the string buffer and terminate it properly. |
| * |
| * Including the "byte" fetch, all operations so far could be |
| * issued at once and be scheduled at the CPU's descression. |
| * Most likely, no-one will soon depend on the data that will be |
| * written in this function. So, no stalls there, either. |
| */ |
| dest[old_len] = byte; |
| dest[old_len+1] = '\0'; |
| } |
| else |
| { |
| /* we need to re-allocate the string buffer |
| * -> let the more generic implementation take care of that part |
| */ |
| |
| /* Depending on the ABI, "byte" is a register value. If we were |
| * to take its address directly, the compiler might decide to |
| * put in on the stack *unconditionally*, even if that would |
| * only be necessary for this block. |
| */ |
| char b = byte; |
| svn_stringbuf_appendbytes(str, &b, 1); |
| } |
| } |
| |
| |
| void |
| svn_stringbuf_appendbytes(svn_stringbuf_t *str, const char *bytes, |
| apr_size_t count) |
| { |
| apr_size_t total_len; |
| void *start_address; |
| |
| if (!count) |
| /* Allow BYTES to be NULL by avoiding passing it to memcpy. */ |
| return; |
| |
| total_len = str->len + count; /* total size needed */ |
| |
| /* svn_stringbuf_ensure adds 1 for null terminator. */ |
| svn_stringbuf_ensure(str, total_len); |
| |
| /* get address 1 byte beyond end of original bytestring */ |
| start_address = (str->data + str->len); |
| |
| memcpy(start_address, bytes, count); |
| str->len = total_len; |
| |
| str->data[str->len] = '\0'; /* We don't know if this is binary |
| data or not, but convention is |
| to null-terminate. */ |
| } |
| |
| void |
| svn_stringbuf_appendfill(svn_stringbuf_t *str, |
| char byte, |
| apr_size_t count) |
| { |
| apr_size_t new_len = str->len + count; |
| svn_stringbuf_ensure(str, new_len); |
| |
| memset(str->data + str->len, byte, count); |
| |
| /* update buffer length and always NUL-terminate it */ |
| str->len = new_len; |
| str->data[new_len] = '\0'; |
| } |
| |
| |
| void |
| svn_stringbuf_appendstr(svn_stringbuf_t *targetstr, |
| const svn_stringbuf_t *appendstr) |
| { |
| svn_stringbuf_appendbytes(targetstr, appendstr->data, appendstr->len); |
| } |
| |
| |
| void |
| svn_stringbuf_appendcstr(svn_stringbuf_t *targetstr, const char *cstr) |
| { |
| svn_stringbuf_appendbytes(targetstr, cstr, strlen(cstr)); |
| } |
| |
| void |
| svn_stringbuf_insert(svn_stringbuf_t *str, |
| apr_size_t pos, |
| const char *bytes, |
| apr_size_t count) |
| { |
| /* For COUNT==0, we allow BYTES to be NULL. It's a no-op in that case. */ |
| if (count == 0) |
| return; |
| |
| /* special case: BYTES overlaps with this string -> copy the source */ |
| if (bytes + count > str->data && bytes < str->data + str->blocksize) |
| bytes = apr_pmemdup(str->pool, bytes, count); |
| |
| if (pos > str->len) |
| pos = str->len; |
| |
| svn_stringbuf_ensure(str, str->len + count); |
| memmove(str->data + pos + count, str->data + pos, str->len - pos + 1); |
| memcpy(str->data + pos, bytes, count); |
| |
| str->len += count; |
| } |
| |
| void |
| svn_stringbuf_remove(svn_stringbuf_t *str, |
| apr_size_t pos, |
| apr_size_t count) |
| { |
| if (pos > str->len) |
| pos = str->len; |
| if (count > str->len - pos) |
| count = str->len - pos; |
| |
| memmove(str->data + pos, str->data + pos + count, str->len - pos - count + 1); |
| str->len -= count; |
| } |
| |
| void |
| svn_stringbuf_replace(svn_stringbuf_t *str, |
| apr_size_t pos, |
| apr_size_t old_count, |
| const char *bytes, |
| apr_size_t new_count) |
| { |
| /* For COUNT==0, we allow BYTES to be NULL. |
| * In that case, this is just a substring removal. */ |
| if (new_count == 0) |
| { |
| svn_stringbuf_remove(str, pos, old_count); |
| return; |
| } |
| |
| /* special case: BYTES overlaps with this string -> copy the source */ |
| if (bytes + new_count > str->data && bytes < str->data + str->blocksize) |
| bytes = apr_pmemdup(str->pool, bytes, new_count); |
| |
| if (pos > str->len) |
| pos = str->len; |
| if (old_count > str->len - pos) |
| old_count = str->len - pos; |
| |
| if (old_count < new_count) |
| { |
| apr_size_t delta = new_count - old_count; |
| svn_stringbuf_ensure(str, str->len + delta); |
| } |
| |
| if (old_count != new_count) |
| memmove(str->data + pos + new_count, str->data + pos + old_count, |
| str->len - pos - old_count + 1); |
| |
| memcpy(str->data + pos, bytes, new_count); |
| str->len += new_count - old_count; |
| } |
| |
| |
| apr_size_t |
| svn_stringbuf_replace_all(svn_stringbuf_t *str, |
| const char *to_find, |
| const char *replacement) |
| { |
| apr_size_t replacements = 0; |
| |
| apr_size_t current = 0; |
| apr_size_t original_length = str->len; |
| |
| apr_size_t to_copy; |
| apr_size_t to_find_len; |
| apr_size_t replacement_len; |
| apr_size_t new_length; |
| |
| /* Early exit. */ |
| const char *pos = strstr(str->data, to_find); |
| if (pos == NULL) |
| return 0; |
| |
| to_find_len = strlen(to_find); |
| replacement_len = strlen(replacement); |
| |
| /* We will store the new contents behind the NUL terminator of the current |
| * data and track the total length in STR->LEN to make the reallocation |
| * code preserve both bits. However, we need to keep the NUL between them |
| * to make strstr stop at that boundary. */ |
| ++str->len; |
| |
| /* Find all occurrences of TO_FIND, copy the bits in between to the target, |
| * separated by REPLACEMENT. */ |
| for ( ; pos; pos = strstr(str->data + current, to_find), ++replacements) |
| { |
| to_copy = pos - str->data - current; |
| svn_stringbuf_ensure(str, str->len + to_copy + replacement_len); |
| |
| if (to_copy) |
| memcpy(str->data + str->len, str->data + current, to_copy); |
| current += to_copy + to_find_len; |
| |
| str->len += to_copy; |
| memcpy(str->data + str->len, replacement, replacement_len); |
| str->len += replacement_len; |
| } |
| |
| /* Copy remainder. */ |
| to_copy = original_length - current; |
| if (to_copy) |
| { |
| svn_stringbuf_ensure(str, str->len + to_copy); |
| memcpy(str->data + str->len, str->data + current, to_copy); |
| str->len += to_copy; |
| } |
| |
| /* Move new contents to the start of the buffer and terminate it. */ |
| new_length = str->len - original_length - 1; |
| memmove(str->data, str->data + original_length + 1, new_length); |
| str->len = new_length; |
| str->data[new_length] = 0; |
| |
| /* Done. */ |
| return replacements; |
| } |
| |
| |
| svn_stringbuf_t * |
| svn_stringbuf_dup(const svn_stringbuf_t *original_string, apr_pool_t *pool) |
| { |
| return (svn_stringbuf_ncreate(original_string->data, |
| original_string->len, pool)); |
| } |
| |
| |
| |
| svn_boolean_t |
| svn_stringbuf_compare(const svn_stringbuf_t *str1, |
| const svn_stringbuf_t *str2) |
| { |
| return string_compare(str1->data, str2->data, str1->len, str2->len); |
| } |
| |
| |
| |
| apr_size_t |
| svn_stringbuf_first_non_whitespace(const svn_stringbuf_t *str) |
| { |
| return string_first_non_whitespace(str->data, str->len); |
| } |
| |
| |
| void |
| svn_stringbuf_strip_whitespace(svn_stringbuf_t *str) |
| { |
| /* Skip (hide) whitespace at the beginning of the string. */ |
| if (svn_ctype_isspace(str->data[0])) |
| { |
| /* Find first non-whitespace character */ |
| apr_size_t offset = string_first_non_whitespace(str->data + 1, |
| str->len - 1) + 1; |
| |
| /* Go ahead! Waste some RAM, we've got pools! :) */ |
| str->data += offset; |
| str->len -= offset; |
| str->blocksize -= offset; |
| } |
| |
| /* Now that we've trimmed the front, trim the end, wasting more RAM. */ |
| while ((str->len > 0) && svn_ctype_isspace(str->data[str->len - 1])) |
| str->len--; |
| str->data[str->len] = '\0'; |
| } |
| |
| |
| apr_size_t |
| svn_stringbuf_find_char_backward(const svn_stringbuf_t *str, char ch) |
| { |
| return find_char_backward(str->data, str->len, ch); |
| } |
| |
| |
| svn_boolean_t |
| svn_string_compare_stringbuf(const svn_string_t *str1, |
| const svn_stringbuf_t *str2) |
| { |
| return string_compare(str1->data, str2->data, str1->len, str2->len); |
| } |
| |
| |
| |
| /*** C string stuff. ***/ |
| |
| void |
| svn_cstring_split_append(apr_array_header_t *array, |
| const char *input, |
| const char *sep_chars, |
| svn_boolean_t chop_whitespace, |
| apr_pool_t *pool) |
| { |
| char *pats; |
| char *p; |
| |
| pats = apr_pstrdup(pool, input); /* strtok wants non-const data */ |
| p = svn_cstring_tokenize(sep_chars, &pats); |
| |
| while (p) |
| { |
| if (chop_whitespace) |
| { |
| while (svn_ctype_isspace(*p)) |
| p++; |
| |
| { |
| char *e = p + (strlen(p) - 1); |
| while ((e >= p) && (svn_ctype_isspace(*e))) |
| e--; |
| *(++e) = '\0'; |
| } |
| } |
| |
| if (p[0] != '\0') |
| APR_ARRAY_PUSH(array, const char *) = p; |
| |
| p = svn_cstring_tokenize(sep_chars, &pats); |
| } |
| |
| return; |
| } |
| |
| |
| apr_array_header_t * |
| svn_cstring_split(const char *input, |
| const char *sep_chars, |
| svn_boolean_t chop_whitespace, |
| apr_pool_t *pool) |
| { |
| apr_array_header_t *a = apr_array_make(pool, 5, sizeof(input)); |
| svn_cstring_split_append(a, input, sep_chars, chop_whitespace, pool); |
| return a; |
| } |
| |
| |
| svn_boolean_t svn_cstring_match_glob_list(const char *str, |
| const apr_array_header_t *list) |
| { |
| int i; |
| |
| for (i = 0; i < list->nelts; i++) |
| { |
| const char *this_pattern = APR_ARRAY_IDX(list, i, char *); |
| |
| if (apr_fnmatch(this_pattern, str, 0) == APR_SUCCESS) |
| return TRUE; |
| } |
| |
| return FALSE; |
| } |
| |
| svn_boolean_t |
| svn_cstring_match_list(const char *str, const apr_array_header_t *list) |
| { |
| int i; |
| |
| for (i = 0; i < list->nelts; i++) |
| { |
| const char *this_str = APR_ARRAY_IDX(list, i, char *); |
| |
| if (strcmp(this_str, str) == 0) |
| return TRUE; |
| } |
| |
| return FALSE; |
| } |
| |
| char * |
| svn_cstring_tokenize(const char *sep, char **str) |
| { |
| char *token; |
| char *next; |
| char csep; |
| |
| /* check parameters */ |
| if ((sep == NULL) || (str == NULL) || (*str == NULL)) |
| return NULL; |
| |
| /* let APR handle edge cases and multiple separators */ |
| csep = *sep; |
| if (csep == '\0' || sep[1] != '\0') |
| return apr_strtok(NULL, sep, str); |
| |
| /* skip characters in sep (will terminate at '\0') */ |
| token = *str; |
| while (*token == csep) |
| ++token; |
| |
| if (!*token) /* no more tokens */ |
| return NULL; |
| |
| /* skip valid token characters to terminate token and |
| * prepare for the next call (will terminate at '\0) |
| */ |
| next = strchr(token, csep); |
| if (next == NULL) |
| { |
| *str = token + strlen(token); |
| } |
| else |
| { |
| *next = '\0'; |
| *str = next + 1; |
| } |
| |
| return token; |
| } |
| |
| int svn_cstring_count_newlines(const char *msg) |
| { |
| int count = 0; |
| const char *p; |
| |
| for (p = msg; *p; p++) |
| { |
| if (*p == '\n') |
| { |
| count++; |
| if (*(p + 1) == '\r') |
| p++; |
| } |
| else if (*p == '\r') |
| { |
| count++; |
| if (*(p + 1) == '\n') |
| p++; |
| } |
| } |
| |
| return count; |
| } |
| |
| char * |
| svn_cstring_join2(const apr_array_header_t *strings, |
| const char *separator, |
| svn_boolean_t trailing_separator, |
| apr_pool_t *pool) |
| { |
| svn_stringbuf_t *new_str = svn_stringbuf_create_empty(pool); |
| size_t sep_len = strlen(separator); |
| int i; |
| |
| for (i = 0; i < strings->nelts; i++) |
| { |
| const char *string = APR_ARRAY_IDX(strings, i, const char *); |
| if (i > 0) |
| svn_stringbuf_appendbytes(new_str, separator, sep_len); |
| svn_stringbuf_appendbytes(new_str, string, strlen(string)); |
| } |
| |
| if (strings->nelts > 0 && trailing_separator) |
| svn_stringbuf_appendbytes(new_str, separator, sep_len); |
| |
| return new_str->data; |
| } |
| |
| int |
| svn_cstring_casecmp(const char *str1, const char *str2) |
| { |
| for (;;) |
| { |
| const int a = *str1++; |
| const int b = *str2++; |
| const int cmp = svn_ctype_casecmp(a, b); |
| if (cmp || !a || !b) |
| return cmp; |
| } |
| } |
| |
| svn_error_t * |
| svn_cstring_strtoui64(apr_uint64_t *n, const char *str, |
| apr_uint64_t minval, apr_uint64_t maxval, |
| int base) |
| { |
| apr_int64_t val; |
| char *endptr; |
| |
| /* We assume errno is thread-safe. */ |
| errno = 0; /* APR-0.9 doesn't always set errno */ |
| |
| /* ### We're throwing away half the number range here. |
| * ### APR needs a apr_strtoui64() function. */ |
| val = apr_strtoi64(str, &endptr, base); |
| if (errno == EINVAL || endptr == str || str[0] == '\0' || *endptr != '\0') |
| return svn_error_createf(SVN_ERR_INCORRECT_PARAMS, NULL, |
| _("Could not convert '%s' into a number"), |
| str); |
| if ((errno == ERANGE && (val == APR_INT64_MIN || val == APR_INT64_MAX)) || |
| val < 0 || (apr_uint64_t)val < minval || (apr_uint64_t)val > maxval) |
| /* ### Mark this for translation when gettext doesn't choke on macros. */ |
| return svn_error_createf(SVN_ERR_INCORRECT_PARAMS, NULL, |
| "Number '%s' is out of range " |
| "'[%" APR_UINT64_T_FMT ", %" APR_UINT64_T_FMT "]'", |
| str, minval, maxval); |
| *n = val; |
| return SVN_NO_ERROR; |
| } |
| |
| svn_error_t * |
| svn_cstring_atoui64(apr_uint64_t *n, const char *str) |
| { |
| return svn_error_trace(svn_cstring_strtoui64(n, str, 0, |
| APR_UINT64_MAX, 10)); |
| } |
| |
| svn_error_t * |
| svn_cstring_atoui(unsigned int *n, const char *str) |
| { |
| apr_uint64_t val; |
| |
| SVN_ERR(svn_cstring_strtoui64(&val, str, 0, APR_UINT32_MAX, 10)); |
| *n = (unsigned int)val; |
| return SVN_NO_ERROR; |
| } |
| |
| svn_error_t * |
| svn_cstring_strtoi64(apr_int64_t *n, const char *str, |
| apr_int64_t minval, apr_int64_t maxval, |
| int base) |
| { |
| apr_int64_t val; |
| char *endptr; |
| |
| /* We assume errno is thread-safe. */ |
| errno = 0; /* APR-0.9 doesn't always set errno */ |
| |
| val = apr_strtoi64(str, &endptr, base); |
| if (errno == EINVAL || endptr == str || str[0] == '\0' || *endptr != '\0') |
| return svn_error_createf(SVN_ERR_INCORRECT_PARAMS, NULL, |
| _("Could not convert '%s' into a number"), |
| str); |
| if ((errno == ERANGE && (val == APR_INT64_MIN || val == APR_INT64_MAX)) || |
| val < minval || val > maxval) |
| /* ### Mark this for translation when gettext doesn't choke on macros. */ |
| return svn_error_createf(SVN_ERR_INCORRECT_PARAMS, NULL, |
| "Number '%s' is out of range " |
| "'[%" APR_INT64_T_FMT ", %" APR_INT64_T_FMT "]'", |
| str, minval, maxval); |
| *n = val; |
| return SVN_NO_ERROR; |
| } |
| |
| svn_error_t * |
| svn_cstring_atoi64(apr_int64_t *n, const char *str) |
| { |
| return svn_error_trace(svn_cstring_strtoi64(n, str, APR_INT64_MIN, |
| APR_INT64_MAX, 10)); |
| } |
| |
| svn_error_t * |
| svn_cstring_atoi(int *n, const char *str) |
| { |
| apr_int64_t val; |
| |
| SVN_ERR(svn_cstring_strtoi64(&val, str, APR_INT32_MIN, APR_INT32_MAX, 10)); |
| *n = (int)val; |
| return SVN_NO_ERROR; |
| } |
| |
| unsigned long |
| svn__strtoul(const char* buffer, const char** end) |
| { |
| unsigned long result = 0; |
| |
| /* this loop will execute in just 2 CPU cycles, confirmed by measurement: |
| 7 macro-ops (max 4 / cycle => 2 cycles) |
| 1 load (max 1 / cycle) |
| 1 jumps (compare + conditional jump == 1 macro op; max 1 / cycle) |
| 2 arithmetic ops (subtract, increment; max 3 / cycle) |
| 2 scale-and-add AGU ops (max 3 / cycle) |
| 1 compiler-generated move operation |
| dependency chain: temp = result * 4 + result; result = temp * 2 + c |
| (2 ops with latency 1 => 2 cycles) |
| */ |
| while (1) |
| { |
| unsigned long c = (unsigned char)*buffer - (unsigned char)'0'; |
| if (c > 9) |
| break; |
| |
| result = result * 10 + c; |
| ++buffer; |
| } |
| |
| *end = buffer; |
| return result; |
| } |
| |
| /* "Precalculated" itoa values for 2 places (including leading zeros). |
| * For maximum performance, make sure all table entries are word-aligned. |
| */ |
| static const char decimal_table[100][4] |
| = { "00", "01", "02", "03", "04", "05", "06", "07", "08", "09" |
| , "10", "11", "12", "13", "14", "15", "16", "17", "18", "19" |
| , "20", "21", "22", "23", "24", "25", "26", "27", "28", "29" |
| , "30", "31", "32", "33", "34", "35", "36", "37", "38", "39" |
| , "40", "41", "42", "43", "44", "45", "46", "47", "48", "49" |
| , "50", "51", "52", "53", "54", "55", "56", "57", "58", "59" |
| , "60", "61", "62", "63", "64", "65", "66", "67", "68", "69" |
| , "70", "71", "72", "73", "74", "75", "76", "77", "78", "79" |
| , "80", "81", "82", "83", "84", "85", "86", "87", "88", "89" |
| , "90", "91", "92", "93", "94", "95", "96", "97", "98", "99"}; |
| |
| /* Copy the two bytes at SOURCE[0] and SOURCE[1] to DEST[0] and DEST[1] */ |
| #define COPY_TWO_BYTES(dest,source)\ |
| memcpy((dest), (source), 2) |
| |
| apr_size_t |
| svn__ui64toa(char * dest, apr_uint64_t number) |
| { |
| char buffer[SVN_INT64_BUFFER_SIZE]; |
| apr_uint32_t reduced; /* used for 32 bit DIV */ |
| char* target; |
| |
| /* Small numbers are by far the most common case. |
| * Therefore, we use special code. |
| */ |
| if (number < 100) |
| { |
| if (number < 10) |
| { |
| dest[0] = (char)('0' + number); |
| dest[1] = 0; |
| return 1; |
| } |
| else |
| { |
| COPY_TWO_BYTES(dest, decimal_table[(apr_size_t)number]); |
| dest[2] = 0; |
| return 2; |
| } |
| } |
| |
| /* Standard code. Write string in pairs of chars back-to-front */ |
| buffer[SVN_INT64_BUFFER_SIZE - 1] = 0; |
| target = &buffer[SVN_INT64_BUFFER_SIZE - 3]; |
| |
| /* Loop may be executed 0 .. 2 times. */ |
| while (number >= 100000000) |
| { |
| /* Number is larger than 100^4, i.e. we can write 4x2 chars. |
| * Also, use 32 bit DIVs as these are about twice as fast. |
| */ |
| reduced = (apr_uint32_t)(number % 100000000); |
| number /= 100000000; |
| |
| COPY_TWO_BYTES(target - 0, decimal_table[reduced % 100]); |
| reduced /= 100; |
| COPY_TWO_BYTES(target - 2, decimal_table[reduced % 100]); |
| reduced /= 100; |
| COPY_TWO_BYTES(target - 4, decimal_table[reduced % 100]); |
| reduced /= 100; |
| COPY_TWO_BYTES(target - 6, decimal_table[reduced % 100]); |
| target -= 8; |
| } |
| |
| /* Now, the number fits into 32 bits, but may still be larger than 99 */ |
| reduced = (apr_uint32_t)(number); |
| while (reduced >= 100) |
| { |
| COPY_TWO_BYTES(target, decimal_table[reduced % 100]); |
| reduced /= 100; |
| target -= 2; |
| } |
| |
| /* The number is now smaller than 100 but larger than 1 */ |
| COPY_TWO_BYTES(target, decimal_table[reduced]); |
| |
| /* Correction for uneven count of places. */ |
| if (reduced < 10) |
| ++target; |
| |
| /* Copy to target */ |
| memcpy(dest, target, &buffer[SVN_INT64_BUFFER_SIZE] - target); |
| return &buffer[SVN_INT64_BUFFER_SIZE] - target - 1; |
| } |
| |
| apr_size_t |
| svn__i64toa(char * dest, apr_int64_t number) |
| { |
| if (number >= 0) |
| return svn__ui64toa(dest, (apr_uint64_t)number); |
| |
| *dest = '-'; |
| return svn__ui64toa(dest + 1, 0 - (apr_uint64_t)number) + 1; |
| } |
| |
| static void |
| ui64toa_sep(apr_uint64_t number, char separator, char *buffer) |
| { |
| apr_size_t length = svn__ui64toa(buffer, number); |
| apr_size_t i; |
| |
| for (i = length; i > 3; i -= 3) |
| { |
| memmove(&buffer[i - 2], &buffer[i - 3], length - i + 3); |
| buffer[i-3] = separator; |
| length++; |
| } |
| |
| buffer[length] = 0; |
| } |
| |
| char * |
| svn__ui64toa_sep(apr_uint64_t number, char separator, apr_pool_t *pool) |
| { |
| char buffer[2 * SVN_INT64_BUFFER_SIZE]; |
| ui64toa_sep(number, separator, buffer); |
| |
| return apr_pstrdup(pool, buffer); |
| } |
| |
| char * |
| svn__i64toa_sep(apr_int64_t number, char separator, apr_pool_t *pool) |
| { |
| char buffer[2 * SVN_INT64_BUFFER_SIZE]; |
| if (number < 0) |
| { |
| buffer[0] = '-'; |
| ui64toa_sep((apr_uint64_t)(-number), separator, &buffer[1]); |
| } |
| else |
| ui64toa_sep((apr_uint64_t)(number), separator, buffer); |
| |
| return apr_pstrdup(pool, buffer); |
| } |
| |
| apr_size_t |
| svn__ui64tobase36(char *dest, apr_uint64_t value) |
| { |
| char *dest_start = dest; |
| if (value < 10) |
| { |
| /* pretty frequent and trivial case. Make it fast. */ |
| *(dest++) = (char)(value) + '0'; |
| } |
| else |
| { |
| char buffer[SVN_INT64_BUFFER_SIZE]; |
| char *p = buffer; |
| |
| /* write result as little-endian to buffer */ |
| while (value > 0) |
| { |
| char c = (char)(value % 36); |
| value /= 36; |
| |
| *p = (c <= 9) ? (c + '0') : (c - 10 + 'a'); |
| ++p; |
| } |
| |
| /* copy as big-endian to DEST */ |
| while (p > buffer) |
| *(dest++) = *(--p); |
| } |
| |
| *dest = '\0'; |
| return dest - dest_start; |
| } |
| |
| apr_uint64_t |
| svn__base36toui64(const char **next, const char *source) |
| { |
| apr_uint64_t result = 0; |
| apr_uint64_t factor = 1; |
| int i = 0; |
| char digits[SVN_INT64_BUFFER_SIZE]; |
| |
| /* convert digits to numerical values and count the number of places. |
| * Also, prevent buffer overflow. */ |
| while (i < sizeof(digits)) |
| { |
| char c = *source; |
| if (c < 'a') |
| { |
| /* includes detection of NUL terminator */ |
| if (c < '0' || c > '9') |
| break; |
| |
| c -= '0'; |
| } |
| else |
| { |
| if (c < 'a' || c > 'z') |
| break; |
| |
| c -= 'a' - 10; |
| } |
| |
| digits[i++] = c; |
| source++; |
| } |
| |
| /* fold digits into the result */ |
| while (i > 0) |
| { |
| result += factor * (apr_uint64_t)digits[--i]; |
| factor *= 36; |
| } |
| |
| if (next) |
| *next = source; |
| |
| return result; |
| } |
| |
| |
| apr_size_t |
| svn_cstring__similarity(const char *stra, const char *strb, |
| svn_membuf_t *buffer, apr_size_t *rlcs) |
| { |
| svn_string_t stringa, stringb; |
| stringa.data = stra; |
| stringa.len = strlen(stra); |
| stringb.data = strb; |
| stringb.len = strlen(strb); |
| return svn_string__similarity(&stringa, &stringb, buffer, rlcs); |
| } |
| |
| apr_size_t |
| svn_string__similarity(const svn_string_t *stringa, |
| const svn_string_t *stringb, |
| svn_membuf_t *buffer, apr_size_t *rlcs) |
| { |
| const char *stra = stringa->data; |
| const char *strb = stringb->data; |
| const apr_size_t lena = stringa->len; |
| const apr_size_t lenb = stringb->len; |
| const apr_size_t total = lena + lenb; |
| const char *enda = stra + lena; |
| const char *endb = strb + lenb; |
| apr_size_t lcs = 0; |
| |
| /* Skip the common prefix ... */ |
| while (stra < enda && strb < endb && *stra == *strb) |
| { |
| ++stra; ++strb; |
| ++lcs; |
| } |
| |
| /* ... and the common suffix */ |
| while (stra < enda && strb < endb) |
| { |
| --enda; --endb; |
| if (*enda != *endb) |
| { |
| ++enda; ++endb; |
| break; |
| } |
| |
| ++lcs; |
| } |
| |
| if (stra < enda && strb < endb) |
| { |
| const apr_size_t resta = enda - stra; |
| const apr_size_t restb = endb - strb; |
| const apr_size_t slots = (resta > restb ? restb : resta); |
| apr_size_t *curr, *prev; |
| const char *pstr; |
| |
| /* The outer loop must iterate on the longer string. */ |
| if (resta < restb) |
| { |
| pstr = stra; |
| stra = strb; |
| strb = pstr; |
| |
| pstr = enda; |
| enda = endb; |
| endb = pstr; |
| } |
| |
| /* Allocate two columns in the LCS matrix |
| ### Optimize this to (slots + 2) instesd of 2 * (slots + 1) */ |
| svn_membuf__ensure(buffer, 2 * (slots + 1) * sizeof(apr_size_t)); |
| svn_membuf__nzero(buffer, (slots + 2) * sizeof(apr_size_t)); |
| prev = buffer->data; |
| curr = prev + slots + 1; |
| |
| /* Calculate LCS length of the remainder */ |
| for (pstr = stra; pstr < enda; ++pstr) |
| { |
| apr_size_t i; |
| for (i = 1; i <= slots; ++i) |
| { |
| if (*pstr == strb[i-1]) |
| curr[i] = prev[i-1] + 1; |
| else |
| curr[i] = (curr[i-1] > prev[i] ? curr[i-1] : prev[i]); |
| } |
| |
| /* Swap the buffers, making the previous one current */ |
| { |
| apr_size_t *const temp = prev; |
| prev = curr; |
| curr = temp; |
| } |
| } |
| |
| lcs += prev[slots]; |
| } |
| |
| if (rlcs) |
| *rlcs = lcs; |
| |
| /* Return similarity ratio rounded to 4 significant digits */ |
| if (total) |
| return ((2 * SVN_STRING__SIM_RANGE_MAX * lcs + total/2) / total); |
| else |
| return SVN_STRING__SIM_RANGE_MAX; |
| } |
| |
| apr_size_t |
| svn_cstring__match_length(const char *a, |
| const char *b, |
| apr_size_t max_len) |
| { |
| apr_size_t pos = 0; |
| |
| #if SVN_UNALIGNED_ACCESS_IS_OK |
| |
| /* Chunky processing is so much faster ... |
| * |
| * We can't make this work on architectures that require aligned access |
| * because A and B will probably have different alignment. So, skipping |
| * the first few chars until alignment is reached is not an option. |
| */ |
| for (; max_len - pos >= sizeof(apr_size_t); pos += sizeof(apr_size_t)) |
| if (*(const apr_size_t*)(a + pos) != *(const apr_size_t*)(b + pos)) |
| break; |
| |
| #endif |
| |
| for (; pos < max_len; ++pos) |
| if (a[pos] != b[pos]) |
| break; |
| |
| return pos; |
| } |
| |
| apr_size_t |
| svn_cstring__reverse_match_length(const char *a, |
| const char *b, |
| apr_size_t max_len) |
| { |
| apr_size_t pos = 0; |
| |
| #if SVN_UNALIGNED_ACCESS_IS_OK |
| |
| /* Chunky processing is so much faster ... |
| * |
| * We can't make this work on architectures that require aligned access |
| * because A and B will probably have different alignment. So, skipping |
| * the first few chars until alignment is reached is not an option. |
| */ |
| for (pos = sizeof(apr_size_t); pos <= max_len; pos += sizeof(apr_size_t)) |
| if (*(const apr_size_t*)(a - pos) != *(const apr_size_t*)(b - pos)) |
| break; |
| |
| pos -= sizeof(apr_size_t); |
| |
| #endif |
| |
| /* If we find a mismatch at -pos, pos-1 characters matched. |
| */ |
| while (++pos <= max_len) |
| if (a[0-pos] != b[0-pos]) |
| return pos - 1; |
| |
| /* No mismatch found -> at least MAX_LEN matching chars. |
| */ |
| return max_len; |
| } |
| |
| const char * |
| svn_cstring_skip_prefix(const char *str, const char *prefix) |
| { |
| apr_size_t len = strlen(prefix); |
| |
| if (strncmp(str, prefix, len) == 0) |
| { |
| return str + len; |
| } |
| else |
| { |
| return NULL; |
| } |
| } |