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+/* yasl, Yet Another String Library for C
+ *
+ * Copyright (c) 2006-2014, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <ctype.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "yasl.h"
+
+
+/// Initialization
+
+/* Create a new yasl string with the content specified by the 'init' pointer
+ * and 'initlen'.
+ * If NULL is used for 'init' the string is initialized with zero bytes.
+ *
+ * The string is always null-termined (all the yasl strings are, always) so
+ * even if you create a yasl string with:
+ *
+ * mystring = yaslnew("abc", 3");
+ *
+ * You can print the string with printf() as there is an implicit \0 at the
+ * end of the string. However the string is binary safe and can contain
+ * \0 characters in the middle, as the length is stored in the yasl header. */
+yastr yaslnew(const void *init, size_t initlen) {
+ struct yastrhdr *sh;
+
+ if (init) {
+ sh = malloc(sizeof(struct yastrhdr) + initlen + 1);
+ } else {
+ sh = calloc(sizeof(struct yastrhdr) + initlen + 1, 1);
+ }
+ if (sh == NULL) { return NULL; }
+
+ sh->len = initlen;
+ sh->free = 0;
+ if (initlen && init) {
+ memcpy(sh->buf, init, initlen);
+ }
+ sh->buf[initlen] = '\0';
+ return (char*)sh->buf;
+}
+
+/* Duplicate a yasl string. */
+yastr yasldup(const yastr s) {
+ return yaslnew(s, yasllen(s));
+}
+
+/* Create an empty (zero length) yasl string. Even in this case the string
+ * always has an implicit null term. */
+yastr yaslempty(void) {
+ return yaslnew("", 0);
+}
+
+/* Create a yasl string from a long long value. It is much faster than:
+ *
+ * yaslcatprintf(yaslempty(), "%lld\n", value);
+ */
+yastr yaslfromlonglong(long long value) {
+ char buf[32], *p;
+ unsigned long long v;
+
+ v = (unsigned long long)((value < 0) ? -value : value);
+ p = buf + 31; /* point to the last character */
+ do {
+ *p-- = '0' + (v%10);
+ v /= 10;
+ } while(v);
+ if (value < 0) { *p-- = '-'; }
+ p++;
+ return yaslnew(p, (size_t)(32 - (p - buf)));
+}
+
+
+/// Querying
+
+/* Compare two yasl strings s1 and s2 with memcmp().
+ *
+ * Return value:
+ *
+ * 1 if s1 > s2.
+ * -1 if s1 < s2.
+ * 0 if s1 and s2 are exactly the same binary string.
+ *
+ * If two strings share exactly the same prefix, but one of the two has
+ * additional characters, the longer string is considered to be greater than
+ * the smaller one. */
+int yaslcmp(const yastr s1, const yastr s2) {
+ size_t l1, l2, minlen;
+ int cmp;
+
+ l1 = yasllen(s1);
+ l2 = yasllen(s2);
+ minlen = (l1 < l2) ? l1 : l2;
+ cmp = memcmp(s1, s2, minlen);
+ if (cmp == 0) { return (int)(l1 - l2); }
+ return cmp;
+}
+
+
+/// Modification
+
+/* Modify a yasl string in-place to make it empty (zero length).
+ * However all the existing buffer is not discarded but set as free space
+ * so that next append operations will not require allocations up to the
+ * number of bytes previously available. */
+void yaslclear(yastr s) {
+ struct yastrhdr *sh = yaslheader(s);
+ sh->free += sh->len;
+ sh->len = 0;
+ sh->buf[0] = '\0';
+}
+
+/* Grow the yasl string to have the specified length. Bytes that were not part
+ * of the original length of the yasl string will be set to zero.
+ *
+ * if the specified length is smaller than the current length, no operation
+ * is performed. */
+yastr yaslgrowzero(yastr s, size_t len) {
+ struct yastrhdr *sh = yaslheader(s);
+ size_t totlen, curlen = sh->len;
+
+ if (len <= curlen) { return s; }
+ s = yaslMakeRoomFor(s, len - curlen);
+ if (s == NULL) { return NULL; }
+
+ /* Make sure added region doesn't contain garbage */
+ sh = yaslheader(s);
+ memset(s + curlen, 0, (len - curlen + 1)); /* also set trailing \0 byte */
+ totlen = sh->len + sh->free;
+ sh->len = len;
+ sh->free = totlen - sh->len;
+ return s;
+}
+
+/* Destructively modify the yasl string 's' to hold the specified binary
+ * safe string pointed by 't' of length 'len' bytes. */
+yastr yaslcpylen(yastr s, const char *t, size_t len) {
+ struct yastrhdr *sh = yaslheader(s);
+ size_t totlen = sh->free + sh->len;
+
+ if (totlen < len) {
+ s = yaslMakeRoomFor(s, len - sh->len);
+ if (s == NULL) { return NULL; }
+ sh = yaslheader(s);
+ totlen = sh->free + sh->len;
+ }
+ memcpy(s, t, len);
+ s[len] = '\0';
+ sh->len = len;
+ sh->free = totlen - len;
+ return s;
+}
+
+/* Like yaslcpylen() but 't' must be a null-termined string so that the length
+ * of the string is obtained with strlen(). */
+yastr yaslcpy(yastr s, const char *t) {
+ return yaslcpylen(s, t, strlen(t));
+}
+
+/* Join an array of C strings using the specified separator (also a C string).
+ * Returns the result as a yasl string. */
+yastr yasljoin(char **argv, int argc, char *sep, size_t seplen) {
+ yastr join = yaslempty();
+
+ for (int j = 0; j < argc; j++) {
+ join = yaslcat(join, argv[j]);
+ if (j != argc - 1) { join = yaslcatlen(join, sep, seplen); }
+ }
+ return join;
+}
+
+/* Like yasljoin, but joins an array of yasl strings. */
+yastr yasljoinyasl(yastr *argv, int argc, const char *sep, size_t seplen) {
+ yastr join = yaslempty();
+
+ for (int j = 0; j < argc; j++) {
+ join = yaslcatyasl(join, argv[j]);
+ if (j != argc - 1) { join = yaslcatlen(join, sep, seplen); }
+ }
+ return join;
+}
+
+/* Modify the string substituting all the occurrences of the set of
+ * characters specified in the 'from' string to the corresponding character
+ * in the 'to' array.
+ *
+ * For instance: yaslmapchars(mystring, "ho", "01", 2)
+ * will have the effect of turning the string "hello" into "0ell1".
+ *
+ * The function returns the yasl string pointer, that is always the same
+ * as the input pointer since no resize is needed. */
+yastr yaslmapchars(yastr s, const char *from, const char *to, size_t setlen) {
+ for (size_t j = 0; j < yasllen(s); j++) {
+ for (size_t i = 0; i < setlen; i++) {
+ if (s[j] == from[i]) {
+ s[j] = to[i];
+ break;
+ }
+ }
+ }
+ return s;
+}
+
+/* Turn the string into a smaller (or equal) string containing only the
+ * substring specified by the 'start' and 'end' indexes.
+ *
+ * start and end can be negative, where -1 means the last character of the
+ * string, -2 the penultimate character, and so forth.
+ *
+ * The interval is inclusive, so the start and end characters will be part
+ * of the resulting string.
+ *
+ * The string is modified in-place.
+ *
+ * Example:
+ *
+ * s = yaslauto("Hello World");
+ * yaslrange(s, 1, -1); => "ello World"
+ */
+void yaslrange(yastr s, ptrdiff_t start, ptrdiff_t end) {
+ struct yastrhdr *sh = yaslheader(s);
+ size_t newlen, len = yasllen(s);
+
+ if (len == 0) { return; }
+ if (start < 0) {
+ start = (ptrdiff_t)len + start;
+ if (start < 0) { start = 0; }
+ }
+ if (end < 0) {
+ end = (ptrdiff_t)len + end;
+ if (end < 0) { end = 0; }
+ }
+ newlen = (size_t)((start > end) ? 0 : (end - start) + 1);
+ if (newlen != 0) {
+ if ((size_t)start >= len) {
+ newlen = 0;
+ } else if ((size_t)end >= len) {
+ end = (ptrdiff_t)len - 1;
+ newlen = (size_t)((start > end) ? 0 : (end - start) + 1);
+ }
+ } else {
+ start = 0;
+ }
+ if (start && newlen) { memmove(sh->buf, sh->buf + start, newlen); }
+ sh->buf[newlen] = 0;
+ sh->free = sh->free + (sh->len - newlen);
+ sh->len = newlen;
+}
+
+/* Apply tolower() to every character of the yasl string 's'. */
+void yasltolower(yastr s) {
+ for (size_t j = 0; j < yasllen(s); j++) {
+ s[j] = (char)tolower(s[j]);
+ }
+}
+
+/* Apply toupper() to every character of the yasl string 's'. */
+void yasltoupper(yastr s) {
+ for (size_t j = 0; j < yasllen(s); j++) {
+ s[j] = (char)toupper(s[j]);
+ }
+}
+
+/* Remove the part of the string from left and from right composed just of
+ * contiguous characters found in 'cset', that is a null terminted C string.
+ *
+ * After the call, the modified yasl string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call.
+ *
+ * Example:
+ *
+ * s = yaslauto("AA...AA.a.aa.aHelloWorld :::");
+ * s = yasltrim(s, "A. :");
+ * printf("%s\n", s);
+ *
+ * Output will be just "Hello World".
+ */
+void yasltrim(yastr s, const char *cset) {
+ struct yastrhdr *sh = yaslheader(s);
+ char *start, *end, *sp, *ep;
+ size_t len;
+
+ sp = start = s;
+ ep = end = s + yasllen(s) - 1;
+ while(sp <= end && strchr(cset, *sp)) { sp++; }
+ while(ep > start && strchr(cset, *ep)) { ep--; }
+ len = (size_t)((sp > ep) ? 0 : ((ep - sp) + 1));
+ if (sh->buf != sp) { memmove(sh->buf, sp, len); }
+ sh->buf[len] = '\0';
+ sh->free = sh->free + (sh->len - len);
+ sh->len = len;
+}
+
+/* Set the yasl string length to the length as obtained with strlen(), so
+ * considering as content only up to the first null term character.
+ *
+ * This function is useful when the yasl string is hacked manually in some
+ * way, like in the following example:
+ *
+ * s = yaslauto("foobar");
+ * s[2] = '\0';
+ * yaslupdatelen(s);
+ * printf("%d\n", yasllen(s));
+ *
+ * The output will be "2", but if we comment out the call to yaslupdatelen()
+ * the output will be "6" as the string was modified but the logical length
+ * remains 6 bytes. */
+void yaslupdatelen(yastr s) {
+ struct yastrhdr *sh = yaslheader(s);
+ size_t reallen = strlen(s);
+ sh->free += (sh->len - reallen);
+ sh->len = reallen;
+}
+
+/* Split a line into arguments, where every argument can be in the
+ * following programming-language REPL-alike form:
+ *
+ * foo bar "newline are supported\n" and "\xff\x00otherstuff"
+ *
+ * The number of arguments is stored into *argc, and an array
+ * of yasl strings is returned.
+ *
+ * The caller should free the resulting array of yasl strings with
+ * yaslfreesplitres().
+ *
+ * Note that yaslcatrepr() is able to convert back a string into
+ * a quoted string in the same format yaslsplitargs() is able to parse.
+ *
+ * The function returns the allocated tokens on success, even when the
+ * input string is empty, or NULL if the input contains unbalanced
+ * quotes or closed quotes followed by non space characters
+ * as in: "foo"bar or "foo'
+ */
+yastr *yaslsplitargs(const char *line, int *argc) {
+ const char *p = line;
+ char *current = NULL;
+ char **vector = NULL;
+
+ *argc = 0;
+ while(1) {
+ /* skip blanks */
+ while(*p && isspace(*p)) { p++; }
+ if (*p) {
+ /* get a token */
+ int inq=0; /* set to 1 if we are in "quotes" */
+ int insq=0; /* set to 1 if we are in 'single quotes' */
+ int done=0;
+
+ if (current == NULL) { current = yaslempty(); }
+ while(!done) {
+ if (inq) {
+ if (*p == '\\' && *(p + 1) == 'x' &&
+ is_hex_digit(*(p + 2)) &&
+ is_hex_digit(*(p + 3)))
+ {
+ unsigned char byte;
+
+ byte = (unsigned char)((hex_digit_to_int(*(p + 2)) * 16) +
+ hex_digit_to_int(*(p + 3)));
+ current = yaslcatlen(current, (char*)&byte, 1);
+ p += 3;
+ } else if (*p == '\\' && *(p + 1)) {
+ char c;
+
+ p++;
+ switch(*p) {
+ case 'n': c = '\n'; break;
+ case 'r': c = '\r'; break;
+ case 't': c = '\t'; break;
+ case 'b': c = '\b'; break;
+ case 'a': c = '\a'; break;
+ default: c = *p; break;
+ }
+ current = yaslcatlen(current, &c, 1);
+ } else if (*p == '"') {
+ /* closing quote must be followed by a space or
+ * nothing at all. */
+ if (*(p + 1) && !isspace(*(p + 1))) { goto err; }
+ done=1;
+ } else if (!*p) {
+ /* unterminated quotes */
+ goto err;
+ } else {
+ current = yaslcatlen(current, p, 1);
+ }
+ } else if (insq) {
+ if (*p == '\\' && *(p + 1) == '\'') {
+ p++;
+ current = yaslcatlen(current, "'", 1);
+ } else if (*p == '\'') {
+ /* closing quote must be followed by a space or
+ * nothing at all. */
+ if (*(p + 1) && !isspace(*(p + 1))) { goto err; }
+ done=1;
+ } else if (!*p) {
+ /* unterminated quotes */
+ goto err;
+ } else {
+ current = yaslcatlen(current, p, 1);
+ }
+ } else {
+ switch(*p) {
+ case ' ':
+ case '\n':
+ case '\r':
+ case '\t':
+ case '\0':
+ done=1;
+ break;
+ case '"':
+ inq=1;
+ break;
+ case '\'':
+ insq=1;
+ break;
+ default:
+ current = yaslcatlen(current, p, 1);
+ break;
+ }
+ }
+ if (*p) { p++; }
+ }
+ /* add the token to the vector */
+ vector = realloc(vector, (unsigned long)((*argc) + 1) * (sizeof (char *)));
+ vector[*argc] = current;
+ (*argc)++;
+ current = NULL;
+ } else {
+ /* Even on empty input string return something not NULL. */
+ if (vector == NULL) { vector = malloc(sizeof(void*)); }
+ return vector;
+ }
+ }
+
+err:
+ while((*argc)--) {
+ yaslfree(vector[*argc]);
+ }
+ free(vector);
+ if (current) { yaslfree(current); }
+ *argc = 0;
+ return NULL;
+}
+
+/* Split 's' with separator in 'sep'. An array
+ * of yasl strings is returned. *count will be set
+ * by reference to the number of tokens returned.
+ *
+ * On out of memory, zero length string, zero length
+ * separator, NULL is returned.
+ *
+ * Note that 'sep' is able to split a string using
+ * a multi-character separator. For example
+ * yaslsplit("foo_-_bar", "_-_"); will return two
+ * elements "foo" and "bar".
+ *
+ * This version of the function is binary-safe but
+ * requires length arguments. yaslsplit() is just the
+ * same function but for zero-terminated strings.
+ */
+yastr *yaslsplitlen(const char *s, size_t len, const char *sep, size_t seplen, size_t *count) {
+ size_t elements = 0, slots = 5, start = 0;
+ yastr *tokens;
+
+ if (seplen < 1) { return NULL; }
+
+ tokens = malloc(sizeof(yastr)*slots);
+ if (tokens == NULL) { return NULL; }
+
+ if (len == 0) {
+ *count = 0;
+ return tokens;
+ }
+ for (size_t j = 0; j < (len - (seplen - 1)); j++) {
+ /* make sure there is room for the next element and the final one */
+ if (slots < elements + 2) {
+ yastr *newtokens;
+
+ slots *= 2;
+ newtokens = realloc(tokens, sizeof(yastr) * slots);
+ if (newtokens == NULL) { goto cleanup; }
+ tokens = newtokens;
+ }
+ /* search the separator */
+ if ((seplen == 1 && *(s + j) == sep[0]) || (memcmp(s + j, sep, seplen) == 0)) {
+ tokens[elements] = yaslnew(s + start, (size_t)(j - start));
+ if (tokens[elements] == NULL) { goto cleanup; }
+ elements++;
+ start = j + seplen;
+ j = j + seplen - 1; /* skip the separator */
+ }
+ }
+ /* Add the final element. We are sure there is room in the tokens array. */
+ tokens[elements] = yaslnew(s + start, (size_t)(len - start));
+ if (tokens[elements] == NULL) { goto cleanup; }
+ elements++;
+ *count = elements;
+ return tokens;
+
+cleanup:
+ {
+ for (size_t i = 0; i < elements; i++) {
+ yaslfree(tokens[i]);
+ }
+ free(tokens);
+ *count = 0;
+ return NULL;
+ }
+}
+
+// Concatenation
+
+/* Append the specified null termianted C string to the yasl string 's'.
+ *
+ * After the call, the passed yasl string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+yastr yaslcat(yastr s, const char *t) {
+ return yaslcatlen(s, t, strlen(t));
+}
+
+/* Append the specified yasl string 't' to the existing yasl string 's'.
+ *
+ * After the call, the modified yasl string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+yastr yaslcatyasl(yastr s, const yastr t) {
+ return yaslcatlen(s, t, yasllen(t));
+}
+
+/* Append the specified binary-safe string pointed by 't' of 'len' bytes to the
+ * end of the specified yasl string 's'.
+ *
+ * After the call, the passed yasl string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+yastr yaslcatlen(yastr s, const void *t, size_t len) {
+ struct yastrhdr *sh;
+ size_t curlen = yasllen(s);
+
+ s = yaslMakeRoomFor(s, len);
+ if (s == NULL) { return NULL; }
+ sh = yaslheader(s);
+ memcpy(s + curlen, t, len);
+ sh->len = curlen + len;
+ sh->free = sh->free - len;
+ s[curlen + len] = '\0';
+ return s;
+}
+
+/* Append to the yasl string "s" an escaped string representation where
+ * all the non-printable characters (tested with isprint()) are turned into
+ * escapes in the form "\n\r\a...." or "\x<hex-number>".
+ *
+ * After the call, the modified yasl string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+yastr yaslcatrepr(yastr s, const char *p, size_t len) {
+ s = yaslcatlen(s, "\"", 1);
+ while(len--) {
+ switch(*p) {
+ case '\\':
+ case '"':
+ s = yaslcatprintf(s, "\\%c", *p);
+ break;
+ case '\n': s = yaslcatlen(s, "\\n", 2); break;
+ case '\r': s = yaslcatlen(s, "\\r", 2); break;
+ case '\t': s = yaslcatlen(s, "\\t", 2); break;
+ case '\a': s = yaslcatlen(s, "\\a", 2); break;
+ case '\b': s = yaslcatlen(s, "\\b", 2); break;
+ default:
+ if (isprint(*p)) {
+ s = yaslcatprintf(s, "%c", *p);
+ } else {
+ s = yaslcatprintf(s, "\\x%02x", (unsigned char)*p);
+ break;
+ }
+ }
+ p++;
+ }
+ return yaslcatlen(s, "\"", 1);
+}
+
+/* Like yaslcatpritf() but gets va_list instead of being variadic. */
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
+yastr yaslcatvprintf(yastr s, const char *fmt, va_list ap) {
+ va_list cpy;
+ char *buf, *t;
+ size_t buflen = 16;
+
+ while(1) {
+ buf = malloc(buflen);
+ if (buf == NULL) { return NULL; }
+ buf[buflen - 2] = '\0';
+ va_copy(cpy, ap);
+ vsnprintf(buf, buflen, fmt, cpy);
+ if (buf[buflen - 2] != '\0') {
+ free(buf);
+ buflen *= 2;
+ continue;
+ }
+ break;
+ }
+ t = yaslcat(s, buf);
+ free(buf);
+ return t;
+}
+#pragma GCC diagnostic warning "-Wformat-nonliteral"
+
+/* Append to the yasl string 's' a string obtained using printf-alike format
+ * specifier.
+ *
+ * After the call, the modified yasl string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call.
+ *
+ * Example:
+ *
+ * s = yaslempty("Sum is: ");
+ * s = yaslcatprintf(s, "%d + %d = %d", a, b, a + b).
+ *
+ * Often you need to create a string from scratch with the printf-alike
+ * format. When this is the need, just use yaslempty() as the target string:
+ *
+ * s = yaslcatprintf(yaslempty(), "... your format ...", args);
+ */
+yastr yaslcatprintf(yastr s, const char *fmt, ...) {
+ va_list ap;
+ char *t;
+ va_start(ap, fmt);
+ t = yaslcatvprintf(s, fmt, ap);
+ va_end(ap);
+ return t;
+}
+
+
+/// Freeing
+
+/* Free a yasl string. No operation is performed if 's' is NULL. */
+void yaslfree(yastr s) {
+ if (s == NULL) { return; }
+ free(yaslheader(s));
+}
+
+/* Free the result returned by yaslsplitlen(), or do nothing if 'tokens' is NULL. */
+void yaslfreesplitres(yastr *tokens, size_t count) {
+ if (!tokens) { return; }
+ while(count--) {
+ yaslfree(tokens[count]);
+ }
+ free(tokens);
+}
+
+
+// Low-level functions
+
+/* Return the total size of the allocation of the specifed yasl string,
+ * including:
+ * 1) The yasl header before the pointer.
+ * 2) The string.
+ * 3) The free buffer at the end if any.
+ * 4) The implicit null term.
+ */
+size_t yaslAllocSize(yastr s) {
+ struct yastrhdr *sh = yaslheader(s);
+
+ return sizeof(*sh) + sh->len + sh->free + 1;
+}
+
+/* Increment the yasl string length and decrements the left free space at the
+ * end of the string according to 'incr'. Also set the null term in the new end
+ * of the string.
+ *
+ * This function is used in order to fix the string length after the
+ * user calls yaslMakeRoomFor(), writes something after the end of
+ * the current string, and finally needs to set the new length.
+ *
+ * Usage example:
+ *
+ * Using yaslIncrLen() and yaslMakeRoomFor() it is possible to mount the
+ * following schema, to cat bytes coming from the kernel to the end of a
+ * yasl string without copying into an intermediate buffer:
+ *
+ * oldlen = yasllen(s);
+ * s = yaslMakeRoomFor(s, BUFFER_SIZE);
+ * nread = read(fd, s + oldlen, BUFFER_SIZE);
+ * ... check for nread <= 0 and handle it ...
+ * yaslIncrLen(s, nread);
+ */
+void yaslIncrLen(yastr s, size_t incr) {
+ struct yastrhdr *sh = yaslheader(s);
+
+ assert(sh->free >= incr);
+ sh->len += incr;
+ sh->free -= incr;
+ s[sh->len] = '\0';
+}
+
+/* Enlarge the free space at the end of the yasl string so that the caller
+ * is sure that after calling this function can overwrite up to addlen
+ * bytes after the end of the string, plus one more byte for nul term.
+ *
+ * Note: this does not change the *length* of the yasl string as returned
+ * by yasllen(), but only the free buffer space we have. */
+yastr yaslMakeRoomFor(yastr s, size_t addlen) {
+ struct yastrhdr *sh, *newsh;
+ size_t free = yaslavail(s);
+ size_t len, newlen;
+
+ if (free >= addlen) { return s; }
+ len = yasllen(s);
+ sh = yaslheader(s);
+ newlen = (len + addlen);
+ if (newlen < YASL_MAX_PREALLOC) {
+ newlen *= 2;
+ } else {
+ newlen += YASL_MAX_PREALLOC;
+ }
+ newsh = realloc(sh, sizeof(struct yastrhdr) + newlen + 1);
+ if (newsh == NULL) { return NULL; }
+
+ newsh->free = newlen - len;
+ return newsh->buf;
+}
+
+/* Reallocate the yasl string so that it has no free space at the end. The
+ * contained string remains not altered, but next concatenation operations
+ * will require a reallocation.
+ *
+ * After the call, the passed yasl string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+yastr yaslRemoveFreeSpace(yastr s) {
+ struct yastrhdr *sh;
+
+ sh = yaslheader(s);
+ sh = realloc(sh, sizeof(struct yastrhdr) + sh->len + 1);
+ sh->free = 0;
+ return sh->buf;
+}
+
+
+/// Low-level helper functions
+
+/* Helper function for yaslsplitargs() that returns non zero if 'c'
+ * is a valid hex digit. */
+int is_hex_digit(char c) {
+ return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') ||
+ (c >= 'A' && c <= 'F');
+}
+
+/* Helper function for yaslsplitargs() that converts a hex digit into an
+ * integer from 0 to 15 */
+int hex_digit_to_int(char c) {
+ switch(c) {
+ case '0': return 0;
+ case '1': return 1;
+ case '2': return 2;
+ case '3': return 3;
+ case '4': return 4;
+ case '5': return 5;
+ case '6': return 6;
+ case '7': return 7;
+ case '8': return 8;
+ case '9': return 9;
+ case 'a': case 'A': return 10;
+ case 'b': case 'B': return 11;
+ case 'c': case 'C': return 12;
+ case 'd': case 'D': return 13;
+ case 'e': case 'E': return 14;
+ case 'f': case 'F': return 15;
+ default: return 0;
+ }
+}
+
generated by cgit v1.2.3-70-g09d2 (git 2.47.0) at 2024-11-24 04:18:42 +0000