Refactor and rename SUBSTR to GETRANGE

SUBSTR is renamed to GETRANGE to have better consistency between command
names (with SETRANGE as its dual). GETRANGE is still aliased as SUBSTR.

src/redis.c

@@ -74,13 +74,14 @@ struct redisCommand readonlyCommandTable[] = {
     {"setnx",setnxCommand,3,REDIS_CMD_DENYOOM,NULL,0,0,0},
     {"setex",setexCommand,4,REDIS_CMD_DENYOOM,NULL,0,0,0},
     {"append",appendCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
-    {"substr",substrCommand,4,0,NULL,1,1,1},
     {"strlen",strlenCommand,2,0,NULL,1,1,1},
     {"del",delCommand,-2,0,NULL,0,0,0},
     {"exists",existsCommand,2,0,NULL,1,1,1},
     {"setbit",setbitCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
     {"getbit",getbitCommand,3,0,NULL,1,1,1},
     {"setrange",setrangeCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
+    {"getrange",getrangeCommand,4,0,NULL,1,1,1},
+    {"substr",getrangeCommand,4,0,NULL,1,1,1},
     {"incr",incrCommand,2,REDIS_CMD_DENYOOM,NULL,1,1,1},
     {"decr",decrCommand,2,REDIS_CMD_DENYOOM,NULL,1,1,1},
     {"mget",mgetCommand,-2,0,NULL,1,-1,1},

src/redis.h

@@ -890,6 +890,7 @@ void existsCommand(redisClient *c);
 void setbitCommand(redisClient *c);
 void getbitCommand(redisClient *c);
 void setrangeCommand(redisClient *c);
+void getrangeCommand(redisClient *c);
 void incrCommand(redisClient *c);
 void decrCommand(redisClient *c);
 void incrbyCommand(redisClient *c);
@@ -967,7 +968,6 @@ void discardCommand(redisClient *c);
 void blpopCommand(redisClient *c);
 void brpopCommand(redisClient *c);
 void appendCommand(redisClient *c);
-void substrCommand(redisClient *c);
 void strlenCommand(redisClient *c);
 void zrankCommand(redisClient *c);
 void zrevrankCommand(redisClient *c);

src/t_string.c

@@ -257,6 +257,43 @@ void setrangeCommand(redisClient *c) {
     addReplyLongLong(c,sdslen(o->ptr));
 }
 
+void getrangeCommand(redisClient *c) {
+    robj *o;
+    long start, end;
+    char *str, llbuf[32];
+    size_t strlen;
+
+    if (getLongFromObjectOrReply(c,c->argv[2],&start,NULL) != REDIS_OK)
+        return;
+    if (getLongFromObjectOrReply(c,c->argv[3],&end,NULL) != REDIS_OK)
+        return;
+    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
+        checkType(c,o,REDIS_STRING)) return;
+
+    if (o->encoding == REDIS_ENCODING_INT) {
+        str = llbuf;
+        strlen = ll2string(llbuf,sizeof(llbuf),(long)o->ptr);
+    } else {
+        str = o->ptr;
+        strlen = sdslen(str);
+    }
+
+    /* Convert negative indexes */
+    if (start < 0) start = strlen+start;
+    if (end < 0) end = strlen+end;
+    if (start < 0) start = 0;
+    if (end < 0) end = 0;
+    if ((unsigned)end >= strlen) end = strlen-1;
+
+    /* Precondition: end >= 0 && end < strlen, so the only condition where
+     * nothing can be returned is: start > end. */
+    if (start > end) {
+        addReply(c,shared.nullbulk);
+    } else {
+        addReplyBulkCBuffer(c,(char*)str+start,end-start+1);
+    }
+}
+
 void mgetCommand(redisClient *c) {
     int j;
 
@@ -400,43 +437,6 @@ void appendCommand(redisClient *c) {
     addReplyLongLong(c,totlen);
 }
 
-void substrCommand(redisClient *c) {
-    robj *o;
-    long start = atoi(c->argv[2]->ptr);
-    long end = atoi(c->argv[3]->ptr);
-    size_t rangelen, strlen;
-    sds range;
-
-    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
-        checkType(c,o,REDIS_STRING)) return;
-
-    o = getDecodedObject(o);
-    strlen = sdslen(o->ptr);
-
-    /* convert negative indexes */
-    if (start < 0) start = strlen+start;
-    if (end < 0) end = strlen+end;
-    if (start < 0) start = 0;
-    if (end < 0) end = 0;
-
-    /* indexes sanity checks */
-    if (start > end || (size_t)start >= strlen) {
-        /* Out of range start or start > end result in null reply */
-        addReply(c,shared.nullbulk);
-        decrRefCount(o);
-        return;
-    }
-    if ((size_t)end >= strlen) end = strlen-1;
-    rangelen = (end-start)+1;
-
-    /* Return the result */
-    addReplySds(c,sdscatprintf(sdsempty(),"$%zu\r\n",rangelen));
-    range = sdsnewlen((char*)o->ptr+start,rangelen);
-    addReplySds(c,range);
-    addReply(c,shared.crlf);
-    decrRefCount(o);
-}
-
 void strlenCommand(redisClient *c) {
     robj *o;
 

tests/unit/basic.tcl

@@ -562,4 +562,40 @@ start_server {tags {"basic"}} {
         r set mykey "hello"
         assert_error "*maximum allowed size*" {r setrange mykey [expr 512*1024*1024-4] world}
     }
+
+    test {SUBSTR basics} {
+        set res {}
+        r set foo "Hello World"
+        lappend res [r substr foo 0 3]
+        lappend res [r substr foo 0 -1]
+        lappend res [r substr foo -4 -1]
+        lappend res [r substr foo 5 3]
+        lappend res [r substr foo 5 5000]
+        lappend res [r substr foo -5000 10000]
+        set _ $res
+    } {Hell {Hello World} orld {} { World} {Hello World}}
+
+    test {SUBSTR against integer encoded values} {
+        r set foo 123
+        r substr foo 0 -2
+    } {12}
+
+    test {SUBSTR fuzzing} {
+        set err {}
+        for {set i 0} {$i < 1000} {incr i} {
+            set bin [randstring 0 1024 binary]
+            set _start [set start [randomInt 1500]]
+            set _end [set end [randomInt 1500]]
+            if {$_start < 0} {set _start "end-[abs($_start)-1]"}
+            if {$_end < 0} {set _end "end-[abs($_end)-1]"}
+            set s1 [string range $bin $_start $_end]
+            r set bin $bin
+            set s2 [r substr bin $start $end]
+            if {$s1 != $s2} {
+                set err "String mismatch"
+                break
+            }
+        }
+        set _ $err
+    } {}
 }

tests/unit/other.tcl

@@ -216,42 +216,6 @@ start_server {tags {"other"}} {
         set _ $err
     } {}
 
-    test {SUBSTR basics} {
-        set res {}
-        r set foo "Hello World"
-        lappend res [r substr foo 0 3]
-        lappend res [r substr foo 0 -1]
-        lappend res [r substr foo -4 -1]
-        lappend res [r substr foo 5 3]
-        lappend res [r substr foo 5 5000]
-        lappend res [r substr foo -5000 10000]
-        set _ $res
-    } {Hell {Hello World} orld {} { World} {Hello World}}
-
-    test {SUBSTR against integer encoded values} {
-        r set foo 123
-        r substr foo 0 -2
-    } {12}
-
-    test {SUBSTR fuzzing} {
-        set err {}
-        for {set i 0} {$i < 1000} {incr i} {
-            set bin [randstring 0 1024 binary]
-            set _start [set start [randomInt 1500]]
-            set _end [set end [randomInt 1500]]
-            if {$_start < 0} {set _start "end-[abs($_start)-1]"}
-            if {$_end < 0} {set _end "end-[abs($_end)-1]"}
-            set s1 [string range $bin $_start $_end]
-            r set bin $bin
-            set s2 [r substr bin $start $end]
-            if {$s1 != $s2} {
-                set err "String mismatch"
-                break
-            }
-        }
-        set _ $err
-    } {}
-
     # Leave the user with a clean DB before to exit
     test {FLUSHDB} {
         set aux {}