diff options
Diffstat (limited to 'lib/dynbuf.c')
| -rw-r--r-- | lib/dynbuf.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/lib/dynbuf.c b/lib/dynbuf.c new file mode 100644 index 000000000..81e30ce94 --- /dev/null +++ b/lib/dynbuf.c @@ -0,0 +1,228 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 2020, Daniel Stenberg, <daniel@haxx.se>, et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at https://curl.haxx.se/docs/copyright.html. + * + * You may opt to use, copy, modify, merge, publish, distribute and/or sell + * copies of the Software, and permit persons to whom the Software is + * furnished to do so, under the terms of the COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ***************************************************************************/ + +#include "curl_setup.h" +#include "strdup.h" +#include "dynbuf.h" + +/* The last 3 #include files should be in this order */ +#include "curl_printf.h" +#include "curl_memory.h" +#include "memdebug.h" + +#define MIN_FIRST_ALLOC 32 + +#define DYNINIT 0xbee51da /* random pattern */ + +/* + * Init a dynbuf struct. + */ +void Curl_dyn_init(struct dynbuf *s, size_t toobig) +{ + DEBUGASSERT(s); + DEBUGASSERT(toobig); + s->bufr = NULL; + s->leng = 0; + s->allc = 0; + s->toobig = toobig; +#ifdef DEBUGBUILD + s->init = DYNINIT; +#endif +} + +/* + * free the buffer and re-init the necessary fields. It doesn't touch the + * 'init' field and thus this buffer can be reused to add data to again. + */ +void Curl_dyn_free(struct dynbuf *s) +{ + DEBUGASSERT(s); + Curl_safefree(s->bufr); + s->leng = s->allc = 0; +} + +/* + * Store/append an chunk of memory to the dynbuf. + */ +static CURLcode dyn_nappend(struct dynbuf *s, + const unsigned char *mem, size_t len) +{ + size_t indx = s->leng; + size_t a = s->allc; + size_t fit = len + indx + 1; /* new string + old string + zero byte */ + + /* try to detect if there's rubbish in the struct */ + DEBUGASSERT(s->init == DYNINIT); + DEBUGASSERT(s->toobig); + DEBUGASSERT(indx < s->toobig); + DEBUGASSERT(!s->leng || s->bufr); + + if(fit > s->toobig) { + Curl_dyn_free(s); + return CURLE_OUT_OF_MEMORY; + } + else if(!a) { + DEBUGASSERT(!indx); + /* first invoke */ + if(fit < MIN_FIRST_ALLOC) + a = MIN_FIRST_ALLOC; + else + a = fit; + } + else { + while(a < fit) + a *= 2; + } + + if(a != s->allc) { + s->bufr = Curl_saferealloc(s->bufr, a); + if(!s->bufr) { + s->leng = s->allc = 0; + return CURLE_OUT_OF_MEMORY; + } + s->allc = a; + } + + if(len) + memcpy(&s->bufr[indx], mem, len); + s->leng = indx + len; + s->bufr[s->leng] = 0; + return CURLE_OK; +} + +/* + * Clears the string, keeps the allocation. This can also be called on a + * buffer that already was freed. + */ +void Curl_dyn_reset(struct dynbuf *s) +{ + DEBUGASSERT(s); + DEBUGASSERT(s->init == DYNINIT); + DEBUGASSERT(!s->leng || s->bufr); + if(s->leng) + s->bufr[0] = 0; + s->leng = 0; +} + +#if 0 +/* + * Specify the size of the tail to keep (number of bytes from the end of the + * buffer). The rest will be dropped. + */ +CURLcode Curl_dyn_tail(struct dynbuf *s, size_t trail) +{ + DEBUGASSERT(s); + DEBUGASSERT(s->init == DYNINIT); + DEBUGASSERT(!s->leng || s->bufr); + if(trail > s->leng) + return CURLE_BAD_FUNCTION_ARGUMENT; + else if(trail == s->leng) + return CURLE_OK; + else if(!trail) { + Curl_dyn_reset(s); + } + else { + memmove(&s->bufr[0], &s->bufr[s->leng - trail], trail); + s->leng = trail; + } + return CURLE_OK; + +} + +#endif + +/* + * Appends a buffer with length. + */ +CURLcode Curl_dyn_addn(struct dynbuf *s, const void *mem, size_t len) +{ + DEBUGASSERT(s); + DEBUGASSERT(s->init == DYNINIT); + DEBUGASSERT(!s->leng || s->bufr); + return dyn_nappend(s, mem, len); +} + +/* + * Append a zero terminated string at the end. + */ +CURLcode Curl_dyn_add(struct dynbuf *s, const char *str) +{ + size_t n = strlen(str); + DEBUGASSERT(s); + DEBUGASSERT(s->init == DYNINIT); + DEBUGASSERT(!s->leng || s->bufr); + return dyn_nappend(s, (unsigned char *)str, n); +} + +/* + * Append a string printf()-style + */ +CURLcode Curl_dyn_addf(struct dynbuf *s, const char *fmt, ...) +{ + char *str; + va_list ap; + va_start(ap, fmt); + str = vaprintf(fmt, ap); /* this allocs a new string to append */ + va_end(ap); + + if(str) { + CURLcode result = dyn_nappend(s, (unsigned char *)str, strlen(str)); + free(str); + return result; + } + /* If we failed, we cleanup the whole buffer and return error */ + Curl_dyn_free(s); + return CURLE_OUT_OF_MEMORY; +} + +/* + * Returns a pointer to the buffer. + */ +char *Curl_dyn_ptr(const struct dynbuf *s) +{ + DEBUGASSERT(s); + DEBUGASSERT(s->init == DYNINIT); + DEBUGASSERT(!s->leng || s->bufr); + return s->leng ? s->bufr : (char *)""; +} + +/* + * Returns an unsigned pointer to the buffer. + */ +unsigned char *Curl_dyn_uptr(const struct dynbuf *s) +{ + DEBUGASSERT(s); + DEBUGASSERT(s->init == DYNINIT); + DEBUGASSERT(!s->leng || s->bufr); + return s->leng ? (unsigned char *)s->bufr : (unsigned char *)""; +} + +/* + * Returns the length of the buffer. + */ +size_t Curl_dyn_len(const struct dynbuf *s) +{ + DEBUGASSERT(s); + DEBUGASSERT(s->init == DYNINIT); + DEBUGASSERT(!s->leng || s->bufr); + return s->leng; +} |