Optimize LRANGE to scan the list starting from the head or the tail in order to trave...

[redis.git] / src / util.c

diff --git a/src/util.c b/src/util.c
index 599dc69005c9da33f497224255cfab34387eb55c..f5a23af2aeacd50a31c906223b0355edb7379ef9 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -1,8 +1,13 @@
-#include "redis.h"
+#include "fmacros.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>

 #include <ctype.h>
 #include <limits.h>
 #include <math.h>
 
 #include <ctype.h>
 #include <limits.h>
 #include <math.h>
 

+#include "util.h"
+

 /* Glob-style pattern matching. */
 int stringmatchlen(const char *pattern, int patternLen,
         const char *string, int stringLen, int nocase)
 /* Glob-style pattern matching. */
 int stringmatchlen(const char *pattern, int patternLen,
         const char *string, int stringLen, int nocase)


@@ -213,6 +218,12 @@ int string2ll(char *s, size_t slen, long long *value) {
     if (plen == slen)
         return 0;
 
     if (plen == slen)
         return 0;
 

+    /* Special case: first and only digit is 0. */
+    if (slen == 1 && p[0] == '0') {
+        if (value != NULL) *value = 0;
+        return 1;
+    }
+

     if (p[0] == '-') {
         negative = 1;
         p++; plen++;
     if (p[0] == '-') {
         negative = 1;
         p++; plen++;


@@ -222,10 +233,13 @@ int string2ll(char *s, size_t slen, long long *value) {
             return 0;
     }
 
             return 0;
     }
 

-    /* First digit should be 1-9. */
+    /* First digit should be 1-9, otherwise the string should just be 0. */

     if (p[0] >= '1' && p[0] <= '9') {
         v = p[0]-'0';
         p++; plen++;
     if (p[0] >= '1' && p[0] <= '9') {
         v = p[0]-'0';
         p++; plen++;

+    } else if (p[0] == '0' && slen == 1) {
+        *value = 0;
+        return 1;

     } else {
         return 0;
     }
     } else {
         return 0;
     }


@@ -247,7 +261,7 @@ int string2ll(char *s, size_t slen, long long *value) {
         return 0;
 
     if (negative) {
         return 0;
 
     if (negative) {

-        if (v > (-(unsigned long long)LLONG_MIN)) /* Overflow. */
+        if (v > ((unsigned long long)(-(LLONG_MIN+1))+1)) /* Overflow. */

             return 0;
         if (value != NULL) *value = -v;
     } else {
             return 0;
         if (value != NULL) *value = -v;
     } else {


@@ -258,6 +272,22 @@ int string2ll(char *s, size_t slen, long long *value) {
     return 1;
 }
 
     return 1;
 }
 

+/* Convert a string into a long. Returns 1 if the string could be parsed into a
+ * (non-overflowing) long, 0 otherwise. The value will be set to the parsed
+ * value when appropriate. */
+int string2l(char *s, size_t slen, long *lval) {
+    long long llval;
+
+    if (!string2ll(s,slen,&llval))
+        return 0;
+
+    if (llval < LONG_MIN || llval > LONG_MAX)
+        return 0;
+
+    *lval = (long)llval;
+    return 1;
+}
+

 /* Convert a double to a string representation. Returns the number of bytes
  * required. The representation should always be parsable by stdtod(3). */
 int d2string(char *buf, size_t len, double value) {
 /* Convert a double to a string representation. Returns the number of bytes
  * required. The representation should always be parsable by stdtod(3). */
 int d2string(char *buf, size_t len, double value) {


@@ -297,44 +327,116 @@ int d2string(char *buf, size_t len, double value) {
     return len;
 }
 
     return len;
 }
 

-/* Check if the sds string 's' can be represented by a long long
- * (that is, is a number that fits into long without any other space or
- * character before or after the digits, so that converting this number
- * back to a string will result in the same bytes as the original string).
- *
- * If so, the function returns REDIS_OK and *llongval is set to the value
- * of the number. Otherwise REDIS_ERR is returned */
-int isStringRepresentableAsLongLong(sds s, long long *llongval) {
-    char buf[32], *endptr;
-    long long value;
-    int slen;
-
-    value = strtoll(s, &endptr, 10);
-    if (endptr[0] != '\0') return REDIS_ERR;
-    slen = ll2string(buf,32,value);
-
-    /* If the number converted back into a string is not identical
-     * then it's not possible to encode the string as integer */
-    if (sdslen(s) != (unsigned)slen || memcmp(buf,s,slen)) return REDIS_ERR;
-    if (llongval) *llongval = value;
-    return REDIS_OK;
+#ifdef UTIL_TEST_MAIN
+#include <assert.h>
+
+void test_string2ll(void) {
+    char buf[32];
+    long long v;
+
+    /* May not start with +. */
+    strcpy(buf,"+1");
+    assert(string2ll(buf,strlen(buf),&v) == 0);
+
+    /* Leading space. */
+    strcpy(buf," 1");
+    assert(string2ll(buf,strlen(buf),&v) == 0);
+
+    /* Trailing space. */
+    strcpy(buf,"1 ");
+    assert(string2ll(buf,strlen(buf),&v) == 0);
+
+    /* May not start with 0. */
+    strcpy(buf,"01");
+    assert(string2ll(buf,strlen(buf),&v) == 0);
+
+    strcpy(buf,"-1");
+    assert(string2ll(buf,strlen(buf),&v) == 1);
+    assert(v == -1);
+
+    strcpy(buf,"0");
+    assert(string2ll(buf,strlen(buf),&v) == 1);
+    assert(v == 0);
+
+    strcpy(buf,"1");
+    assert(string2ll(buf,strlen(buf),&v) == 1);
+    assert(v == 1);
+
+    strcpy(buf,"99");
+    assert(string2ll(buf,strlen(buf),&v) == 1);
+    assert(v == 99);
+
+    strcpy(buf,"-99");
+    assert(string2ll(buf,strlen(buf),&v) == 1);
+    assert(v == -99);
+
+    strcpy(buf,"-9223372036854775808");
+    assert(string2ll(buf,strlen(buf),&v) == 1);
+    assert(v == LLONG_MIN);
+
+    strcpy(buf,"-9223372036854775809"); /* overflow */
+    assert(string2ll(buf,strlen(buf),&v) == 0);
+
+    strcpy(buf,"9223372036854775807");
+    assert(string2ll(buf,strlen(buf),&v) == 1);
+    assert(v == LLONG_MAX);
+
+    strcpy(buf,"9223372036854775808"); /* overflow */
+    assert(string2ll(buf,strlen(buf),&v) == 0);

 }
 
 }
 

-int isStringRepresentableAsLong(sds s, long *longval) {
-    long long ll;
+void test_string2l(void) {
+    char buf[32];
+    long v;
+
+    /* May not start with +. */
+    strcpy(buf,"+1");
+    assert(string2l(buf,strlen(buf),&v) == 0);
+
+    /* May not start with 0. */
+    strcpy(buf,"01");
+    assert(string2l(buf,strlen(buf),&v) == 0);
+
+    strcpy(buf,"-1");
+    assert(string2l(buf,strlen(buf),&v) == 1);
+    assert(v == -1);
+
+    strcpy(buf,"0");
+    assert(string2l(buf,strlen(buf),&v) == 1);
+    assert(v == 0);
+
+    strcpy(buf,"1");
+    assert(string2l(buf,strlen(buf),&v) == 1);
+    assert(v == 1);

 
 

-    if (isStringRepresentableAsLongLong(s,&ll) == REDIS_ERR) return REDIS_ERR;
-    if (ll < LONG_MIN || ll > LONG_MAX) return REDIS_ERR;
-    *longval = (long)ll;
-    return REDIS_OK;
+    strcpy(buf,"99");
+    assert(string2l(buf,strlen(buf),&v) == 1);
+    assert(v == 99);
+
+    strcpy(buf,"-99");
+    assert(string2l(buf,strlen(buf),&v) == 1);
+    assert(v == -99);
+
+#if LONG_MAX != LLONG_MAX
+    strcpy(buf,"-2147483648");
+    assert(string2l(buf,strlen(buf),&v) == 1);
+    assert(v == LONG_MIN);
+
+    strcpy(buf,"-2147483649"); /* overflow */
+    assert(string2l(buf,strlen(buf),&v) == 0);
+
+    strcpy(buf,"2147483647");
+    assert(string2l(buf,strlen(buf),&v) == 1);
+    assert(v == LONG_MAX);
+
+    strcpy(buf,"2147483648"); /* overflow */
+    assert(string2l(buf,strlen(buf),&v) == 0);
+#endif

 }
 
 }
 

-int isObjectRepresentableAsLongLong(robj *o, long long *llongval) {
-    redisAssert(o->type == REDIS_STRING);
-    if (o->encoding == REDIS_ENCODING_INT) {
-        if (llongval) *llongval = (long) o->ptr;
-        return REDIS_OK;
-    } else {
-        return isStringRepresentableAsLongLong(o->ptr,llongval);
-    }
+int main(int argc, char **argv) {
+    test_string2ll();
+    test_string2l();
+    return 0;

 }
 }

+#endif