syncio.c read / write functions reworked for correctness and performance.

[redis.git] / src / sds.c

diff --git a/src/sds.c b/src/sds.c
index 77052966ceb79e72355df042f400648d35131829..bc6aa6b2f25cc8988b405782a3e25d50e08ea704 100644 (file)
--- a/src/sds.c
+++ b/src/sds.c
@@ -26,28 +26,16 @@
  * 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.
  * 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 <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>

+#include <assert.h>

 #include "sds.h"
 #include "zmalloc.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;
 
 sds sdsnewlen(const void *init, size_t initlen) {
     struct sdshdr *sh;
 


@@ -56,11 +44,7 @@ sds sdsnewlen(const void *init, size_t initlen) {
     } else {
         sh = zcalloc(sizeof(struct sdshdr)+initlen+1);
     }
     } else {
         sh = zcalloc(sizeof(struct sdshdr)+initlen+1);
     }

-#ifdef SDS_ABORT_ON_OOM
-    if (sh == NULL) sdsOomAbort();
-#else

     if (sh == NULL) return NULL;
     if (sh == NULL) return NULL;

-#endif

     sh->len = initlen;
     sh->free = 0;
     if (initlen && init)
     sh->len = initlen;
     sh->free = 0;
     if (initlen && init)


@@ -101,7 +85,13 @@ void sdsclear(sds s) {
     sh->buf[0] = '\0';
 }
 
     sh->buf[0] = '\0';
 }
 

-static sds sdsMakeRoomFor(sds s, size_t addlen) {
+/* Enlarge the free space at the end of the sds 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 *size* of the sds string as returned
+ * by sdslen(), but only the free buffer space we have. */
+sds sdsMakeRoomFor(sds s, size_t addlen) {

     struct sdshdr *sh, *newsh;
     size_t free = sdsavail(s);
     size_t len, newlen;
     struct sdshdr *sh, *newsh;
     size_t free = sdsavail(s);
     size_t len, newlen;


@@ -109,18 +99,67 @@ static sds sdsMakeRoomFor(sds s, size_t addlen) {
     if (free >= addlen) return s;
     len = sdslen(s);
     sh = (void*) (s-(sizeof(struct sdshdr)));
     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);
     newsh = zrealloc(sh, sizeof(struct sdshdr)+newlen+1);

-#ifdef SDS_ABORT_ON_OOM
-    if (newsh == NULL) sdsOomAbort();
-#else

     if (newsh == NULL) return NULL;
     if (newsh == NULL) return NULL;

-#endif

 
     newsh->free = newlen - len;
     return newsh->buf;
 }
 
 
     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) {
 /* 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) {


@@ -158,6 +197,10 @@ sds sdscat(sds s, char *t) {
     return sdscatlen(s, t, strlen(t));
 }
 
     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;
 sds sdscpylen(sds s, char *t, size_t len) {
     struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
     size_t totlen = sh->free+sh->len;


@@ -186,11 +229,7 @@ sds sdscatvprintf(sds s, const char *fmt, va_list ap) {
 
     while(1) {
         buf = zmalloc(buflen);
 
     while(1) {
         buf = zmalloc(buflen);

-#ifdef SDS_ABORT_ON_OOM
-        if (buf == NULL) sdsOomAbort();
-#else

         if (buf == NULL) return NULL;
         if (buf == NULL) return NULL;

-#endif

         buf[buflen-2] = '\0';
         va_copy(cpy,ap);
         vsnprintf(buf, buflen, fmt, cpy);
         buf[buflen-2] = '\0';
         va_copy(cpy,ap);
         vsnprintf(buf, buflen, fmt, cpy);


@@ -310,11 +349,7 @@ sds *sdssplitlen(char *s, int len, char *sep, int seplen, int *count) {
     if (seplen < 1 || len < 0) return NULL;
 
     tokens = zmalloc(sizeof(sds)*slots);
     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;
     if (tokens == NULL) return NULL;

-#endif

 
     if (len == 0) {
         *count = 0;
 
     if (len == 0) {
         *count = 0;


@@ -327,25 +362,13 @@ sds *sdssplitlen(char *s, int len, char *sep, int seplen, int *count) {
 
             slots *= 2;
             newtokens = zrealloc(tokens,sizeof(sds)*slots);
 
             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);
             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 */
             elements++;
             start = j+seplen;
             j = j+seplen-1; /* skip the separator */


@@ -353,18 +376,11 @@ sds *sdssplitlen(char *s, int len, char *sep, int seplen, int *count) {
     }
     /* Add the final element. We are sure there is room in the tokens array. */
     tokens[elements] = sdsnewlen(s+start,len-start);
     }
     /* 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;
 
     elements++;
     *count = elements;
     return tokens;
 

-#ifndef SDS_ABORT_ON_OOM

 cleanup:
     {
         int i;
 cleanup:
     {
         int i;


@@ -373,7 +389,6 @@ cleanup:
         *count = 0;
         return NULL;
     }
         *count = 0;
         return NULL;
     }

-#endif

 }
 
 void sdsfreesplitres(sds *tokens, int count) {
 }
 
 void sdsfreesplitres(sds *tokens, int count) {


@@ -477,7 +492,8 @@ sds *sdssplitargs(char *line, int *argc) {
         while(*p && isspace(*p)) p++;
         if (*p) {
             /* get a token */
         while(*p && isspace(*p)) p++;
         if (*p) {
             /* get a token */

-            int inq=0; /* set to 1 if we are in "quotes" */
+            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 = sdsempty();
             int done=0;
 
             if (current == NULL) current = sdsempty();


@@ -507,7 +523,23 @@ sds *sdssplitargs(char *line, int *argc) {
                         }
                         current = sdscatlen(current,&c,1);
                     } else if (*p == '"') {
                         }
                         current = sdscatlen(current,&c,1);
                     } else if (*p == '"') {

-                        /* closing quote must be followed by a space */
+                        /* 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 = sdscatlen(current,p,1);
+                    }
+                } else if (insq) {
+                    if (*p == '\\' && *(p+1) == '\'') {
+                        p++;
+                        current = sdscatlen(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) {
                         if (*(p+1) && !isspace(*(p+1))) goto err;
                         done=1;
                     } else if (!*p) {


@@ -528,6 +560,9 @@ sds *sdssplitargs(char *line, int *argc) {
                     case '"':
                         inq=1;
                         break;
                     case '"':
                         inq=1;
                         break;

+                    case '\'':
+                        insq=1;
+                        break;

                     default:
                         current = sdscatlen(current,p,1);
                         break;
                     default:
                         current = sdscatlen(current,p,1);
                         break;


@@ -589,6 +624,7 @@ sds sdsmapchars(sds s, char *from, char *to, size_t setlen) {
 
 int main(void) {
     {
 
 int main(void) {
     {

+        struct sdshdr *sh;

         sds x = sdsnew("foo"), y;
 
         test_cond("Create a string and obtain the length",
         sds x = sdsnew("foo"), y;
 
         test_cond("Create a string and obtain the length",


@@ -668,7 +704,26 @@ int main(void) {
         x = sdsnew("aar");
         y = sdsnew("bar");
         test_cond("sdscmp(bar,bar)", sdscmp(x,y) < 0)
         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()
     }
     test_report()

+    return 0;

 }
 #endif
 }
 #endif