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+/***************************************************************************
+ * _ _ ____ _
+ * 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;
+}