| /* 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. |
| */ |
| |
| /** |
| * @file util_varbuf.h |
| * @brief Apache resizable variable length buffer library |
| * |
| * @defgroup APACHE_CORE_VARBUF Variable length buffer library |
| * @ingroup APACHE_CORE |
| * |
| * This set of functions provides resizable buffers. While the primary |
| * usage is with NUL-terminated strings, most functions also work with |
| * arbitrary binary data. |
| * |
| * @{ |
| */ |
| |
| #ifndef AP_VARBUF_H |
| #define AP_VARBUF_H |
| |
| #include "apr.h" |
| #include "apr_allocator.h" |
| |
| #include "httpd.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| #define AP_VARBUF_UNKNOWN APR_SIZE_MAX |
| struct ap_varbuf_info; |
| |
| /** A resizable buffer. */ |
| struct ap_varbuf { |
| /** The actual buffer; will point to a const '\\0' if avail == 0 and |
| * to memory of the same lifetime as the pool otherwise. */ |
| char *buf; |
| |
| /** Allocated size of the buffer (minus one for the final \\0); |
| * must only be changed using ap_varbuf_grow(). */ |
| apr_size_t avail; |
| |
| /** Length of string in buffer, or AP_VARBUF_UNKNOWN. This determines how |
| * much memory is copied by ap_varbuf_grow() and where |
| * ap_varbuf_strmemcat() will append to the buffer. */ |
| apr_size_t strlen; |
| |
| /** The pool for memory allocations and for registering the cleanup; |
| * the buffer memory will be released when this pool is cleared. */ |
| apr_pool_t *pool; |
| |
| /** Opaque info for memory allocation. */ |
| struct ap_varbuf_info *info; |
| }; |
| |
| /** |
| * Initialize a resizable buffer. It is safe to re-initialize a previously |
| * used ap_varbuf. The old buffer will be released when the corresponding |
| * pool is cleared. The buffer remains usable until the pool is cleared, |
| * even if the ap_varbuf was located on the stack and has gone out of scope. |
| * @param pool The pool to allocate small buffers from and to register |
| * the cleanup with |
| * @param vb Pointer to the ap_varbuf struct |
| * @param init_size The initial size of the buffer (see ap_varbuf_grow() for |
| * details) |
| */ |
| AP_DECLARE(void) ap_varbuf_init(apr_pool_t *pool, struct ap_varbuf *vb, |
| apr_size_t init_size); |
| |
| /** |
| * Grow a resizable buffer. If the vb->buf cannot be grown in place, it will |
| * be reallocated and the first vb->strlen + 1 bytes of memory will be copied |
| * to the new location. If vb->strlen == AP_VARBUF_UNKNOWN, the whole buffer |
| * is copied. |
| * @param vb Pointer to the ap_varbuf struct |
| * @param new_size The minimum new size of the buffer |
| * @note ap_varbuf_grow() will usually at least double vb->buf's size with |
| * every invocation in order to reduce reallocations. |
| * @note ap_varbuf_grow() will use pool memory for small and allocator |
| * mem nodes for larger allocations. |
| * @note ap_varbuf_grow() will call vb->pool's abort function if out of memory. |
| */ |
| AP_DECLARE(void) ap_varbuf_grow(struct ap_varbuf *vb, apr_size_t new_size); |
| |
| /** |
| * Release memory from a ap_varbuf immediately, if possible. |
| * This allows to free large buffers before the corresponding pool is |
| * cleared. Only larger allocations using mem nodes will be freed. |
| * @param vb Pointer to the ap_varbuf struct |
| * @note After ap_varbuf_free(), vb must not be used unless ap_varbuf_init() |
| * is called again. |
| */ |
| AP_DECLARE(void) ap_varbuf_free(struct ap_varbuf *vb); |
| |
| /** |
| * Concatenate a string to an ap_varbuf. vb->strlen determines where |
| * the string is appended in the buffer. If vb->strlen == AP_VARBUF_UNKNOWN, |
| * the string will be appended at the first NUL byte in the buffer. |
| * If len == 0, ap_varbuf_strmemcat() does nothing. |
| * @param vb Pointer to the ap_varbuf struct |
| * @param str The string to append; must be at least len bytes long |
| * @param len The number of characters of *str to concatenate to the buf |
| * @note vb->strlen will be set to the length of the new string |
| * @note if len != 0, vb->buf will always be NUL-terminated |
| */ |
| AP_DECLARE(void) ap_varbuf_strmemcat(struct ap_varbuf *vb, const char *str, |
| int len); |
| |
| /** |
| * Duplicate an ap_varbuf's content into pool memory. |
| * @param p The pool to allocate from |
| * @param vb The ap_varbuf to copy from |
| * @param prepend An optional buffer to prepend (may be NULL) |
| * @param prepend_len Length of prepend |
| * @param append An optional buffer to append (may be NULL) |
| * @param append_len Length of append |
| * @param new_len Where to store the length of the resulting string |
| * (may be NULL) |
| * @return The new string |
| * @note ap_varbuf_pdup() uses vb->strlen to determine how much memory to |
| * copy. It works even if 0-bytes are embedded in vb->buf, prepend, or |
| * append. |
| * @note If vb->strlen equals AP_VARBUF_UNKNOWN, it will be set to |
| * strlen(vb->buf). |
| */ |
| AP_DECLARE(char *) ap_varbuf_pdup(apr_pool_t *p, struct ap_varbuf *vb, |
| const char *prepend, apr_size_t prepend_len, |
| const char *append, apr_size_t append_len, |
| apr_size_t *new_len); |
| |
| |
| /** |
| * Concatenate a string to an ap_varbuf. |
| * @param vb Pointer to the ap_varbuf struct |
| * @param str The string to append |
| * @note vb->strlen will be set to the length of the new string |
| */ |
| #define ap_varbuf_strcat(vb, str) ap_varbuf_strmemcat(vb, str, strlen(str)) |
| |
| /** |
| * Perform string substitutions based on regexp match, using an ap_varbuf. |
| * This function behaves like ap_pregsub(), but appends to an ap_varbuf |
| * instead of allocating the result from a pool. |
| * @param vb The ap_varbuf to which the string will be appended |
| * @param input An arbitrary string containing $1 through $9. These are |
| * replaced with the corresponding matched sub-expressions |
| * @param source The string that was originally matched to the regex |
| * @param nmatch The nmatch returned from ap_pregex |
| * @param pmatch The pmatch array returned from ap_pregex |
| * @param maxlen The maximum string length to append to vb, 0 for unlimited |
| * @return APR_SUCCESS if successful |
| * @note Just like ap_pregsub(), this function does not copy the part of |
| * *source before the matching part (i.e. the first pmatch[0].rm_so |
| * characters). |
| * @note If vb->strlen equals AP_VARBUF_UNKNOWN, it will be set to |
| * strlen(vb->buf) first. |
| */ |
| AP_DECLARE(apr_status_t) ap_varbuf_regsub(struct ap_varbuf *vb, |
| const char *input, |
| const char *source, |
| apr_size_t nmatch, |
| ap_regmatch_t pmatch[], |
| apr_size_t maxlen); |
| |
| /** |
| * Read a line from an ap_configfile_t and append it to an ap_varbuf. |
| * @param vb Pointer to the ap_varbuf struct |
| * @param cfp Pointer to the ap_configfile_t |
| * @param max_len Maximum line length, including leading/trailing whitespace |
| * @return See ap_cfg_getline() |
| * @note vb->strlen will be set to the length of the line |
| * @note If vb->strlen equals AP_VARBUF_UNKNOWN, it will be set to |
| * strlen(vb->buf) first. |
| */ |
| AP_DECLARE(apr_status_t) ap_varbuf_cfg_getline(struct ap_varbuf *vb, |
| ap_configfile_t *cfp, |
| apr_size_t max_len); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* !AP_VARBUF_H */ |
| /** @} */ |
