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Diffstat (limited to 'main/strings.c')
| -rw-r--r-- | main/strings.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/main/strings.c b/main/strings.c new file mode 100644 index 000000000..1fd1cac54 --- /dev/null +++ b/main/strings.c @@ -0,0 +1,219 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 2008, Digium, Inc. + * + * Tilghman Lesher <tlesher@digium.com> + * + * See http://www.asterisk.org for more information about + * the Asterisk project. Please do not directly contact + * any of the maintainers of this project for assistance; + * the project provides a web site, mailing lists and IRC + * channels for your use. + * + * This program is free software, distributed under the terms of +* the GNU General Public License Version 2. See the LICENSE file + * at the top of the source tree. + */ + +/*! \file + * + * \brief String manipulation API + * + * \author Tilghman Lesher <tilghman@digium.com> + */ + +/*** MAKEOPTS +<category name="MENUSELECT_CFLAGS" displayname="Compiler Flags" positive_output="yes" remove_on_change=".lastclean"> + <member name="DEBUG_OPAQUE" displayname="Change ast_str internals to detect improper usage"> + <defaultenabled>yes</defaultenabled> + </member> +</category> + ***/ + +#include "asterisk.h" + +ASTERISK_FILE_VERSION(__FILE__, "$Revision$") + +#include "asterisk/strings.h" +#include "asterisk/pbx.h" + +/*! + * core handler for dynamic strings. + * This is not meant to be called directly, but rather through the + * various wrapper macros + * ast_str_set(...) + * ast_str_append(...) + * ast_str_set_va(...) + * ast_str_append_va(...) + */ + +int __ast_str_helper(struct ast_str **buf, size_t max_len, + int append, const char *fmt, va_list ap) +{ + int res, need; +#ifdef DEBUG_OPAQUE + int offset = (append && (*buf)->len2) ? (*buf)->used2 : 0; +#else + int offset = (append && (*buf)->len) ? (*buf)->used : 0; +#endif + va_list aq; + + do { + if (max_len < 0) { +#ifdef DEBUG_OPAQUE + max_len = (*buf)->len2; /* don't exceed the allocated space */ +#else + max_len = (*buf)->len; /* don't exceed the allocated space */ +#endif + } + /* + * Ask vsnprintf how much space we need. Remember that vsnprintf + * does not count the final '\0' so we must add 1. + */ + va_copy(aq, ap); +#ifdef DEBUG_OPAQUE + res = vsnprintf((*buf)->str2 + offset, (*buf)->len2 - offset, fmt, aq); +#else + res = vsnprintf((*buf)->str + offset, (*buf)->len - offset, fmt, aq); +#endif + + need = res + offset + 1; + /* + * If there is not enough space and we are below the max length, + * reallocate the buffer and return a message telling to retry. + */ +#ifdef DEBUG_OPAQUE + if (need > (*buf)->len2 && (max_len == 0 || (*buf)->len2 < max_len) ) { +#else + if (need > (*buf)->len && (max_len == 0 || (*buf)->len < max_len) ) { +#endif + if (max_len && max_len < need) { /* truncate as needed */ + need = max_len; + } else if (max_len == 0) { /* if unbounded, give more room for next time */ + need += 16 + need / 4; + } + if (0) { /* debugging */ +#ifdef DEBUG_OPAQUE + ast_verbose("extend from %d to %d\n", (int)(*buf)->len2, need); +#else + ast_verbose("extend from %d to %d\n", (int)(*buf)->len, need); +#endif + } + if (ast_str_make_space(buf, need)) { +#ifdef DEBUG_OPAQUE + ast_verbose("failed to extend from %d to %d\n", (int)(*buf)->len2, need); +#else + ast_verbose("failed to extend from %d to %d\n", (int)(*buf)->len, need); +#endif + return AST_DYNSTR_BUILD_FAILED; + } +#ifdef DEBUG_OPAQUE + (*buf)->str2[offset] = '\0'; /* Truncate the partial write. */ +#else + (*buf)->str[offset] = '\0'; /* Truncate the partial write. */ +#endif + + /* Restart va_copy before calling vsnprintf() again. */ + va_end(aq); + continue; + } + break; + } while (1); + /* update space used, keep in mind the truncation */ +#ifdef DEBUG_OPAQUE + (*buf)->used2 = (res + offset > (*buf)->len2) ? (*buf)->len2 : res + offset; +#else + (*buf)->used = (res + offset > (*buf)->len) ? (*buf)->len : res + offset; +#endif + + return res; +} + +void ast_str_substitute_variables(struct ast_str **buf, size_t maxlen, struct ast_channel *chan, const char *template) +{ + int first = 1; +#ifdef DEBUG_OPAQUE + do { + ast_str_make_space(buf, maxlen ? maxlen : + (first ? strlen(template) * 2 : (*buf)->len2 * 2)); + pbx_substitute_variables_helper_full(chan, NULL, template, (*buf)->str2, (*buf)->len2 - 1, &((*buf)->used2)); + first = 0; + } while (maxlen == 0 && (*buf)->len2 - 5 < (*buf)->used2); +#else + do { + ast_str_make_space(buf, maxlen ? maxlen : + (first ? strlen(template) * 2 : (*buf)->len * 2)); + pbx_substitute_variables_helper_full(chan, NULL, template, (*buf)->str, (*buf)->len - 1, &((*buf)->used)); + first = 0; + } while (maxlen == 0 && (*buf)->len - 5 < (*buf)->used); +#endif +} + +char *__ast_str_helper2(struct ast_str **buf, size_t maxlen, const char *src, size_t maxsrc, int append, int escapecommas) +{ + int dynamic = 0; +#ifdef DEBUG_OPAQUE + char *ptr = append ? &((*buf)->str2[(*buf)->used2]) : (*buf)->str2; +#else + char *ptr = append ? &((*buf)->str[(*buf)->used]) : (*buf)->str; +#endif + + if (!maxlen) { + dynamic = 1; +#ifdef DEBUG_OPAQUE + maxlen = (*buf)->len2; +#else + maxlen = (*buf)->len; +#endif + } + + while (*src && maxsrc && maxlen && (!escapecommas || (maxlen - 1))) { + if (escapecommas && (*src == '\\' || *src == ',')) { + *ptr++ = '\\'; + maxlen--; +#ifdef DEBUG_OPAQUE + (*buf)->used2++; +#else + (*buf)->used++; +#endif + } + *ptr++ = *src++; + maxsrc--; + maxlen--; +#ifdef DEBUG_OPAQUE + (*buf)->used2++; +#else + (*buf)->used++; +#endif + if (dynamic && (!maxlen || (escapecommas && !(maxlen - 1)))) { +#ifdef DEBUG_OPAQUE + size_t old = (*buf)->len2; + if (ast_str_make_space(buf, (*buf)->len2 * 2)) { + /* If the buffer can't be extended, end it. */ + break; + } +#else + size_t old = (*buf)->len; + if (ast_str_make_space(buf, (*buf)->len * 2)) { + /* If the buffer can't be extended, end it. */ + break; + } +#endif + /* What we extended the buffer by */ + maxlen = old; + } + } + if (__builtin_expect(!(maxsrc && maxlen), 0)) { + ptr--; + } + *ptr = '\0'; +#ifdef DEBUG_OPAQUE + (*buf)->used2--; + return (*buf)->str2; +#else + (*buf)->used--; + return (*buf)->str; +#endif +} + |