* 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.
- *
- * History:
- *
- * - 22 March 2011: History section created on top of sds.c
- * - 22 March 2011: Fixed a problem with "\xab" escapes convertion in
- * function sdssplitargs().
*/
-#define SDS_ABORT_ON_OOM
-
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
+#include <assert.h>
#include "sds.h"
#include "zmalloc.h"
-static void sdsOomAbort(void) {
- fprintf(stderr,"SDS: Out Of Memory (SDS_ABORT_ON_OOM defined)\n");
- abort();
-}
-
sds sdsnewlen(const void *init, size_t initlen) {
struct sdshdr *sh;
} else {
sh = zcalloc(sizeof(struct sdshdr)+initlen+1);
}
-#ifdef SDS_ABORT_ON_OOM
- if (sh == NULL) sdsOomAbort();
-#else
if (sh == NULL) return NULL;
-#endif
sh->len = initlen;
sh->free = 0;
if (initlen && init)
*
* Note: this does not change the *size* of the sds string as returned
* by sdslen(), but only the free buffer space we have. */
-static sds sdsMakeRoomFor(sds s, size_t addlen) {
+sds sdsMakeRoomFor(sds s, size_t addlen) {
struct sdshdr *sh, *newsh;
size_t free = sdsavail(s);
size_t len, newlen;
if (free >= addlen) return s;
len = sdslen(s);
sh = (void*) (s-(sizeof(struct sdshdr)));
- newlen = (len+addlen)*2;
+ newlen = (len+addlen);
+ if (newlen < SDS_MAX_PREALLOC)
+ newlen *= 2;
+ else
+ newlen += SDS_MAX_PREALLOC;
newsh = zrealloc(sh, sizeof(struct sdshdr)+newlen+1);
-#ifdef SDS_ABORT_ON_OOM
- if (newsh == NULL) sdsOomAbort();
-#else
if (newsh == NULL) return NULL;
-#endif
newsh->free = newlen - len;
return newsh->buf;
}
+/* Reallocate the sds 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. */
+sds sdsRemoveFreeSpace(sds s) {
+ struct sdshdr *sh;
+
+ sh = (void*) (s-(sizeof(struct sdshdr)));
+ sh = zrealloc(sh, sizeof(struct sdshdr)+sh->len+1);
+ sh->free = 0;
+ return sh->buf;
+}
+
+size_t sdsAllocSize(sds s) {
+ struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
+
+ return sizeof(*sh)+sh->len+sh->free+1;
+}
+
+/* Increment the sds length and decrements the left free space at the
+ * end of the string accordingly 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 sdsMakeRoomFor(), writes something after the end of
+ * the current string, and finally needs to set the new length.
+ *
+ * Note: it is possible to use a negative increment in order to
+ * right-trim the string.
+ *
+ * Using sdsIncrLen() and sdsMakeRoomFor() it is possible to mount the
+ * following schema to cat bytes coming from the kerenl to the end of an
+ * sds string new things without copying into an intermediate buffer:
+ *
+ * oldlen = sdslen(s);
+ * s = sdsMakeRoomFor(s, BUFFER_SIZE);
+ * nread = read(fd, s+oldlen, BUFFER_SIZE);
+ * ... check for nread <= 0 and handle it ...
+ * sdsIncrLen(s, nhread);
+ */
+void sdsIncrLen(sds s, int incr) {
+ struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
+
+ assert(sh->free >= incr);
+ sh->len += incr;
+ sh->free -= incr;
+ assert(sh->free >= 0);
+ s[sh->len] = '\0';
+}
+
/* Grow the sds to have the specified length. Bytes that were not part of
* the original length of the sds will be set to zero. */
sds sdsgrowzero(sds s, size_t len) {
return sdscatlen(s, t, strlen(t));
}
+sds sdscatsds(sds s, sds t) {
+ return sdscatlen(s, t, sdslen(t));
+}
+
sds sdscpylen(sds s, char *t, size_t len) {
struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
size_t totlen = sh->free+sh->len;
while(1) {
buf = zmalloc(buflen);
-#ifdef SDS_ABORT_ON_OOM
- if (buf == NULL) sdsOomAbort();
-#else
if (buf == NULL) return NULL;
-#endif
buf[buflen-2] = '\0';
va_copy(cpy,ap);
vsnprintf(buf, buflen, fmt, cpy);
if (seplen < 1 || len < 0) return NULL;
tokens = zmalloc(sizeof(sds)*slots);
-#ifdef SDS_ABORT_ON_OOM
- if (tokens == NULL) sdsOomAbort();
-#else
if (tokens == NULL) return NULL;
-#endif
if (len == 0) {
*count = 0;
slots *= 2;
newtokens = zrealloc(tokens,sizeof(sds)*slots);
- if (newtokens == NULL) {
-#ifdef SDS_ABORT_ON_OOM
- sdsOomAbort();
-#else
- goto cleanup;
-#endif
- }
+ 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] = sdsnewlen(s+start,j-start);
- if (tokens[elements] == NULL) {
-#ifdef SDS_ABORT_ON_OOM
- sdsOomAbort();
-#else
- goto cleanup;
-#endif
- }
+ 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] = sdsnewlen(s+start,len-start);
- if (tokens[elements] == NULL) {
-#ifdef SDS_ABORT_ON_OOM
- sdsOomAbort();
-#else
- goto cleanup;
-#endif
- }
+ if (tokens[elements] == NULL) goto cleanup;
elements++;
*count = elements;
return tokens;
-#ifndef SDS_ABORT_ON_OOM
cleanup:
{
int i;
*count = 0;
return NULL;
}
-#endif
}
void sdsfreesplitres(sds *tokens, int count) {
int main(void) {
{
+ struct sdshdr *sh;
sds x = sdsnew("foo"), y;
test_cond("Create a string and obtain the length",
x = sdsnew("aar");
y = sdsnew("bar");
test_cond("sdscmp(bar,bar)", sdscmp(x,y) < 0)
+
+ {
+ int oldfree;
+
+ sdsfree(x);
+ x = sdsnew("0");
+ sh = (void*) (x-(sizeof(struct sdshdr)));
+ test_cond("sdsnew() free/len buffers", sh->len == 1 && sh->free == 0);
+ x = sdsMakeRoomFor(x,1);
+ sh = (void*) (x-(sizeof(struct sdshdr)));
+ test_cond("sdsMakeRoomFor()", sh->len == 1 && sh->free > 0);
+ oldfree = sh->free;
+ x[1] = '1';
+ sdsIncrLen(x,1);
+ test_cond("sdsIncrLen() -- content", x[0] == '0' && x[1] == '1');
+ test_cond("sdsIncrLen() -- len", sh->len == 2);
+ test_cond("sdsIncrLen() -- free", sh->free == oldfree-1);
+ }
}
test_report()
+ return 0;
}
#endif
projects / redis.git / blobdiff