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redis/src/t_string.c

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/*
* Copyright (c) 2009-2012, 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.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* 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 "server.h"
#include <math.h> /* isnan(), isinf() */
/* Forward declarations */
int getGenericCommand(client *c);
/*-----------------------------------------------------------------------------
* String Commands
*----------------------------------------------------------------------------*/
static int checkStringLength(client *c, long long size) {
if (!mustObeyClient(c) && size > server.proto_max_bulk_len) {
addReplyError(c,"string exceeds maximum allowed size (proto-max-bulk-len)");
return C_ERR;
}
return C_OK;
}
/* The setGenericCommand() function implements the SET operation with different
* options and variants. This function is called in order to implement the
* following commands: SET, SETEX, PSETEX, SETNX, GETSET.
*
* 'flags' changes the behavior of the command (NX, XX or GET, see below).
*
* 'expire' represents an expire to set in form of a Redis object as passed
* by the user. It is interpreted according to the specified 'unit'.
*
* 'ok_reply' and 'abort_reply' is what the function will reply to the client
* if the operation is performed, or when it is not because of NX or
* XX flags.
*
* If ok_reply is NULL "+OK" is used.
* If abort_reply is NULL, "$-1" is used. */
#define OBJ_NO_FLAGS 0
#define OBJ_SET_NX (1<<0) /* Set if key not exists. */
#define OBJ_SET_XX (1<<1) /* Set if key exists. */
#define OBJ_EX (1<<2) /* Set if time in seconds is given */
#define OBJ_PX (1<<3) /* Set if time in ms in given */
#define OBJ_KEEPTTL (1<<4) /* Set and keep the ttl */
#define OBJ_SET_GET (1<<5) /* Set if want to get key before set */
#define OBJ_EXAT (1<<6) /* Set if timestamp in second is given */
#define OBJ_PXAT (1<<7) /* Set if timestamp in ms is given */
#define OBJ_PERSIST (1<<8) /* Set if we need to remove the ttl */
/* Forward declaration */
static int getExpireMillisecondsOrReply(client *c, robj *expire, int flags, int unit, long long *milliseconds);
void setGenericCommand(client *c, int flags, robj *key, robj *val, robj *expire, int unit, robj *ok_reply, robj *abort_reply) {
long long milliseconds = 0; /* initialized to avoid any harmness warning */
int found = 0;
int setkey_flags = 0;
if (expire && getExpireMillisecondsOrReply(c, expire, flags, unit, &milliseconds) != C_OK) {
return;
}
if (flags & OBJ_SET_GET) {
if (getGenericCommand(c) == C_ERR) return;
}
found = (lookupKeyWrite(c->db,key) != NULL);
if ((flags & OBJ_SET_NX && found) ||
(flags & OBJ_SET_XX && !found))
{
if (!(flags & OBJ_SET_GET)) {
addReply(c, abort_reply ? abort_reply : shared.null[c->resp]);
}
return;
}
setkey_flags |= (flags & OBJ_KEEPTTL) ? SETKEY_KEEPTTL : 0;
setkey_flags |= found ? SETKEY_ALREADY_EXIST : SETKEY_DOESNT_EXIST;
setKey(c,c->db,key,val,setkey_flags);
server.dirty++;
notifyKeyspaceEvent(NOTIFY_STRING,"set",key,c->db->id);
if (expire) {
setExpire(c,c->db,key,milliseconds);
/* Propagate as SET Key Value PXAT millisecond-timestamp if there is
* EX/PX/EXAT/PXAT flag. */
robj *milliseconds_obj = createStringObjectFromLongLong(milliseconds);
rewriteClientCommandVector(c, 5, shared.set, key, val, shared.pxat, milliseconds_obj);
decrRefCount(milliseconds_obj);
notifyKeyspaceEvent(NOTIFY_GENERIC,"expire",key,c->db->id);
}
if (!(flags & OBJ_SET_GET)) {
addReply(c, ok_reply ? ok_reply : shared.ok);
}
/* Propagate without the GET argument (Isn't needed if we had expire since in that case we completely re-written the command argv) */
if ((flags & OBJ_SET_GET) && !expire) {
int argc = 0;
int j;
robj **argv = zmalloc((c->argc-1)*sizeof(robj*));
for (j=0; j < c->argc; j++) {
char *a = c->argv[j]->ptr;
/* Skip GET which may be repeated multiple times. */
if (j >= 3 &&
(a[0] == 'g' || a[0] == 'G') &&
(a[1] == 'e' || a[1] == 'E') &&
(a[2] == 't' || a[2] == 'T') && a[3] == '\0')
continue;
argv[argc++] = c->argv[j];
incrRefCount(c->argv[j]);
}
replaceClientCommandVector(c, argc, argv);
}
}
/*
* Extract the `expire` argument of a given GET/SET command as an absolute timestamp in milliseconds.
*
* "client" is the client that sent the `expire` argument.
* "expire" is the `expire` argument to be extracted.
* "flags" represents the behavior of the command (e.g. PX or EX).
* "unit" is the original unit of the given `expire` argument (e.g. UNIT_SECONDS).
* "milliseconds" is output argument.
*
* If return C_OK, "milliseconds" output argument will be set to the resulting absolute timestamp.
* If return C_ERR, an error reply has been added to the given client.
*/
static int getExpireMillisecondsOrReply(client *c, robj *expire, int flags, int unit, long long *milliseconds) {
int ret = getLongLongFromObjectOrReply(c, expire, milliseconds, NULL);
if (ret != C_OK) {
return ret;
}
if (*milliseconds <= 0 || (unit == UNIT_SECONDS && *milliseconds > LLONG_MAX / 1000)) {
/* Negative value provided or multiplication is gonna overflow. */
addReplyErrorExpireTime(c);
return C_ERR;
}
if (unit == UNIT_SECONDS) *milliseconds *= 1000;
if ((flags & OBJ_PX) || (flags & OBJ_EX)) {
*milliseconds += mstime();
}
if (*milliseconds <= 0) {
/* Overflow detected. */
addReplyErrorExpireTime(c);
return C_ERR;
}
return C_OK;
}
#define COMMAND_GET 0
#define COMMAND_SET 1
/*
* The parseExtendedStringArgumentsOrReply() function performs the common validation for extended
* string arguments used in SET and GET command.
*
* Get specific commands - PERSIST/DEL
* Set specific commands - XX/NX/GET
* Common commands - EX/EXAT/PX/PXAT/KEEPTTL
*
* Function takes pointers to client, flags, unit, pointer to pointer of expire obj if needed
* to be determined and command_type which can be COMMAND_GET or COMMAND_SET.
*
* If there are any syntax violations C_ERR is returned else C_OK is returned.
*
* Input flags are updated upon parsing the arguments. Unit and expire are updated if there are any
* EX/EXAT/PX/PXAT arguments. Unit is updated to millisecond if PX/PXAT is set.
*/
int parseExtendedStringArgumentsOrReply(client *c, int *flags, int *unit, robj **expire, int command_type) {
int j = command_type == COMMAND_GET ? 2 : 3;
for (; j < c->argc; j++) {
char *opt = c->argv[j]->ptr;
robj *next = (j == c->argc-1) ? NULL : c->argv[j+1];
if ((opt[0] == 'n' || opt[0] == 'N') &&
(opt[1] == 'x' || opt[1] == 'X') && opt[2] == '\0' &&
!(*flags & OBJ_SET_XX) && (command_type == COMMAND_SET))
{
*flags |= OBJ_SET_NX;
} else if ((opt[0] == 'x' || opt[0] == 'X') &&
(opt[1] == 'x' || opt[1] == 'X') && opt[2] == '\0' &&
!(*flags & OBJ_SET_NX) && (command_type == COMMAND_SET))
{
*flags |= OBJ_SET_XX;
} else if ((opt[0] == 'g' || opt[0] == 'G') &&
(opt[1] == 'e' || opt[1] == 'E') &&
(opt[2] == 't' || opt[2] == 'T') && opt[3] == '\0' &&
(command_type == COMMAND_SET))
{
*flags |= OBJ_SET_GET;
} else if (!strcasecmp(opt, "KEEPTTL") && !(*flags & OBJ_PERSIST) &&
!(*flags & OBJ_EX) && !(*flags & OBJ_EXAT) &&
!(*flags & OBJ_PX) && !(*flags & OBJ_PXAT) && (command_type == COMMAND_SET))
{
*flags |= OBJ_KEEPTTL;
} else if (!strcasecmp(opt,"PERSIST") && (command_type == COMMAND_GET) &&
!(*flags & OBJ_EX) && !(*flags & OBJ_EXAT) &&
!(*flags & OBJ_PX) && !(*flags & OBJ_PXAT) &&
!(*flags & OBJ_KEEPTTL))
{
*flags |= OBJ_PERSIST;
} else if ((opt[0] == 'e' || opt[0] == 'E') &&
(opt[1] == 'x' || opt[1] == 'X') && opt[2] == '\0' &&
!(*flags & OBJ_KEEPTTL) && !(*flags & OBJ_PERSIST) &&
!(*flags & OBJ_EXAT) && !(*flags & OBJ_PX) &&
!(*flags & OBJ_PXAT) && next)
{
*flags |= OBJ_EX;
*expire = next;
j++;
} else if ((opt[0] == 'p' || opt[0] == 'P') &&
(opt[1] == 'x' || opt[1] == 'X') && opt[2] == '\0' &&
!(*flags & OBJ_KEEPTTL) && !(*flags & OBJ_PERSIST) &&
!(*flags & OBJ_EX) && !(*flags & OBJ_EXAT) &&
!(*flags & OBJ_PXAT) && next)
{
*flags |= OBJ_PX;
*unit = UNIT_MILLISECONDS;
*expire = next;
j++;
} else if ((opt[0] == 'e' || opt[0] == 'E') &&
(opt[1] == 'x' || opt[1] == 'X') &&
(opt[2] == 'a' || opt[2] == 'A') &&
(opt[3] == 't' || opt[3] == 'T') && opt[4] == '\0' &&
!(*flags & OBJ_KEEPTTL) && !(*flags & OBJ_PERSIST) &&
!(*flags & OBJ_EX) && !(*flags & OBJ_PX) &&
!(*flags & OBJ_PXAT) && next)
{
*flags |= OBJ_EXAT;
*expire = next;
j++;
} else if ((opt[0] == 'p' || opt[0] == 'P') &&
(opt[1] == 'x' || opt[1] == 'X') &&
(opt[2] == 'a' || opt[2] == 'A') &&
(opt[3] == 't' || opt[3] == 'T') && opt[4] == '\0' &&
!(*flags & OBJ_KEEPTTL) && !(*flags & OBJ_PERSIST) &&
!(*flags & OBJ_EX) && !(*flags & OBJ_EXAT) &&
!(*flags & OBJ_PX) && next)
{
*flags |= OBJ_PXAT;
*unit = UNIT_MILLISECONDS;
*expire = next;
j++;
} else {
addReplyErrorObject(c,shared.syntaxerr);
return C_ERR;
}
}
return C_OK;
}
/* SET key value [NX] [XX] [KEEPTTL] [GET] [EX <seconds>] [PX <milliseconds>]
* [EXAT <seconds-timestamp>][PXAT <milliseconds-timestamp>] */
void setCommand(client *c) {
robj *expire = NULL;
int unit = UNIT_SECONDS;
int flags = OBJ_NO_FLAGS;
if (parseExtendedStringArgumentsOrReply(c,&flags,&unit,&expire,COMMAND_SET) != C_OK) {
return;
}
c->argv[2] = tryObjectEncoding(c->argv[2]);
setGenericCommand(c,flags,c->argv[1],c->argv[2],expire,unit,NULL,NULL);
}
void setnxCommand(client *c) {
c->argv[2] = tryObjectEncoding(c->argv[2]);
setGenericCommand(c,OBJ_SET_NX,c->argv[1],c->argv[2],NULL,0,shared.cone,shared.czero);
}
void setexCommand(client *c) {
c->argv[3] = tryObjectEncoding(c->argv[3]);
setGenericCommand(c,OBJ_EX,c->argv[1],c->argv[3],c->argv[2],UNIT_SECONDS,NULL,NULL);
}
void psetexCommand(client *c) {
c->argv[3] = tryObjectEncoding(c->argv[3]);
setGenericCommand(c,OBJ_PX,c->argv[1],c->argv[3],c->argv[2],UNIT_MILLISECONDS,NULL,NULL);
}
int getGenericCommand(client *c) {
robj *o;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.null[c->resp])) == NULL)
return C_OK;
if (checkType(c,o,OBJ_STRING)) {
return C_ERR;
}
addReplyBulk(c,o);
return C_OK;
}
void getCommand(client *c) {
getGenericCommand(c);
}
/*
* GETEX <key> [PERSIST][EX seconds][PX milliseconds][EXAT seconds-timestamp][PXAT milliseconds-timestamp]
*
* The getexCommand() function implements extended options and variants of the GET command. Unlike GET
* command this command is not read-only.
*
* The default behavior when no options are specified is same as GET and does not alter any TTL.
*
* Only one of the below options can be used at a given time.
*
* 1. PERSIST removes any TTL associated with the key.
* 2. EX Set expiry TTL in seconds.
* 3. PX Set expiry TTL in milliseconds.
* 4. EXAT Same like EX instead of specifying the number of seconds representing the TTL
* (time to live), it takes an absolute Unix timestamp
* 5. PXAT Same like PX instead of specifying the number of milliseconds representing the TTL
* (time to live), it takes an absolute Unix timestamp
*
* Command would either return the bulk string, error or nil.
*/
void getexCommand(client *c) {
robj *expire = NULL;
int unit = UNIT_SECONDS;
int flags = OBJ_NO_FLAGS;
if (parseExtendedStringArgumentsOrReply(c,&flags,&unit,&expire,COMMAND_GET) != C_OK) {
return;
}
robj *o;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.null[c->resp])) == NULL)
return;
if (checkType(c,o,OBJ_STRING)) {
return;
}
/* Validate the expiration time value first */
long long milliseconds = 0;
if (expire && getExpireMillisecondsOrReply(c, expire, flags, unit, &milliseconds) != C_OK) {
return;
}
/* We need to do this before we expire the key or delete it */
addReplyBulk(c,o);
/* This command is never propagated as is. It is either propagated as PEXPIRE[AT],DEL,UNLINK or PERSIST.
* This why it doesn't need special handling in feedAppendOnlyFile to convert relative expire time to absolute one. */
if (((flags & OBJ_PXAT) || (flags & OBJ_EXAT)) && checkAlreadyExpired(milliseconds)) {
/* When PXAT/EXAT absolute timestamp is specified, there can be a chance that timestamp
* has already elapsed so delete the key in that case. */
int deleted = server.lazyfree_lazy_expire ? dbAsyncDelete(c->db, c->argv[1]) :
dbSyncDelete(c->db, c->argv[1]);
serverAssert(deleted);
robj *aux = server.lazyfree_lazy_expire ? shared.unlink : shared.del;
rewriteClientCommandVector(c,2,aux,c->argv[1]);
signalModifiedKey(c, c->db, c->argv[1]);
notifyKeyspaceEvent(NOTIFY_GENERIC, "del", c->argv[1], c->db->id);
server.dirty++;
} else if (expire) {
setExpire(c,c->db,c->argv[1],milliseconds);
/* Propagate as PXEXPIREAT millisecond-timestamp if there is
* EX/PX/EXAT/PXAT flag and the key has not expired. */
robj *milliseconds_obj = createStringObjectFromLongLong(milliseconds);
rewriteClientCommandVector(c,3,shared.pexpireat,c->argv[1],milliseconds_obj);
decrRefCount(milliseconds_obj);
signalModifiedKey(c, c->db, c->argv[1]);
notifyKeyspaceEvent(NOTIFY_GENERIC,"expire",c->argv[1],c->db->id);
server.dirty++;
} else if (flags & OBJ_PERSIST) {
if (removeExpire(c->db, c->argv[1])) {
signalModifiedKey(c, c->db, c->argv[1]);
rewriteClientCommandVector(c, 2, shared.persist, c->argv[1]);
notifyKeyspaceEvent(NOTIFY_GENERIC,"persist",c->argv[1],c->db->id);
server.dirty++;
}
}
}
void getdelCommand(client *c) {
if (getGenericCommand(c) == C_ERR) return;
int deleted = server.lazyfree_lazy_user_del ? dbAsyncDelete(c->db, c->argv[1]) :
dbSyncDelete(c->db, c->argv[1]);
if (deleted) {
/* Propagate as DEL/UNLINK command */
robj *aux = server.lazyfree_lazy_user_del ? shared.unlink : shared.del;
rewriteClientCommandVector(c,2,aux,c->argv[1]);
signalModifiedKey(c, c->db, c->argv[1]);
notifyKeyspaceEvent(NOTIFY_GENERIC, "del", c->argv[1], c->db->id);
server.dirty++;
}
}
void getsetCommand(client *c) {
if (getGenericCommand(c) == C_ERR) return;
c->argv[2] = tryObjectEncoding(c->argv[2]);
setKey(c,c->db,c->argv[1],c->argv[2],0);
notifyKeyspaceEvent(NOTIFY_STRING,"set",c->argv[1],c->db->id);
server.dirty++;
/* Propagate as SET command */
rewriteClientCommandArgument(c,0,shared.set);
}
void setrangeCommand(client *c) {
robj *o;
long offset;
sds value = c->argv[3]->ptr;
if (getLongFromObjectOrReply(c,c->argv[2],&offset,NULL) != C_OK)
return;
if (offset < 0) {
addReplyError(c,"offset is out of range");
return;
}
o = lookupKeyWrite(c->db,c->argv[1]);
if (o == NULL) {
/* Return 0 when setting nothing on a non-existing string */
if (sdslen(value) == 0) {
addReply(c,shared.czero);
return;
}
/* Return when the resulting string exceeds allowed size */
if (checkStringLength(c,offset+sdslen(value)) != C_OK)
return;
o = createObject(OBJ_STRING,sdsnewlen(NULL, offset+sdslen(value)));
dbAdd(c->db,c->argv[1],o);
} else {
size_t olen;
/* Key exists, check type */
if (checkType(c,o,OBJ_STRING))
return;
/* Return existing string length when setting nothing */
olen = stringObjectLen(o);
if (sdslen(value) == 0) {
addReplyLongLong(c,olen);
return;
}
/* Return when the resulting string exceeds allowed size */
if (checkStringLength(c,offset+sdslen(value)) != C_OK)
return;
/* Create a copy when the object is shared or encoded. */
o = dbUnshareStringValue(c->db,c->argv[1],o);
}
if (sdslen(value) > 0) {
o->ptr = sdsgrowzero(o->ptr,offset+sdslen(value));
memcpy((char*)o->ptr+offset,value,sdslen(value));
signalModifiedKey(c,c->db,c->argv[1]);
notifyKeyspaceEvent(NOTIFY_STRING,
"setrange",c->argv[1],c->db->id);
server.dirty++;
}
addReplyLongLong(c,sdslen(o->ptr));
}
void getrangeCommand(client *c) {
robj *o;
long long start, end;
char *str, llbuf[32];
size_t strlen;
if (getLongLongFromObjectOrReply(c,c->argv[2],&start,NULL) != C_OK)
return;
if (getLongLongFromObjectOrReply(c,c->argv[3],&end,NULL) != C_OK)
return;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptybulk)) == NULL ||
checkType(c,o,OBJ_STRING)) return;
if (o->encoding == OBJ_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 && end < 0 && start > end) {
addReply(c,shared.emptybulk);
return;
}
if (start < 0) start = strlen+start;
if (end < 0) end = strlen+end;
if (start < 0) start = 0;
if (end < 0) end = 0;
if ((unsigned long long)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 || strlen == 0) {
addReply(c,shared.emptybulk);
} else {
addReplyBulkCBuffer(c,(char*)str+start,end-start+1);
}
}
void mgetCommand(client *c) {
int j;
addReplyArrayLen(c,c->argc-1);
for (j = 1; j < c->argc; j++) {
robj *o = lookupKeyRead(c->db,c->argv[j]);
if (o == NULL) {
addReplyNull(c);
} else {
if (o->type != OBJ_STRING) {
addReplyNull(c);
} else {
addReplyBulk(c,o);
}
}
}
}
void msetGenericCommand(client *c, int nx) {
int j;
if ((c->argc % 2) == 0) {
addReplyErrorArity(c);
return;
}
/* Handle the NX flag. The MSETNX semantic is to return zero and don't
* set anything if at least one key already exists. */
if (nx) {
for (j = 1; j < c->argc; j += 2) {
if (lookupKeyWrite(c->db,c->argv[j]) != NULL) {
addReply(c, shared.czero);
return;
}
}
}
for (j = 1; j < c->argc; j += 2) {
c->argv[j+1] = tryObjectEncoding(c->argv[j+1]);
setKey(c,c->db,c->argv[j],c->argv[j+1],0);
notifyKeyspaceEvent(NOTIFY_STRING,"set",c->argv[j],c->db->id);
}
server.dirty += (c->argc-1)/2;
addReply(c, nx ? shared.cone : shared.ok);
}
void msetCommand(client *c) {
msetGenericCommand(c,0);
}
void msetnxCommand(client *c) {
msetGenericCommand(c,1);
}
void incrDecrCommand(client *c, long long incr) {
long long value, oldvalue;
robj *o, *new;
o = lookupKeyWrite(c->db,c->argv[1]);
if (checkType(c,o,OBJ_STRING)) return;
if (getLongLongFromObjectOrReply(c,o,&value,NULL) != C_OK) return;
oldvalue = value;
if ((incr < 0 && oldvalue < 0 && incr < (LLONG_MIN-oldvalue)) ||
(incr > 0 && oldvalue > 0 && incr > (LLONG_MAX-oldvalue))) {
addReplyError(c,"increment or decrement would overflow");
return;
}
value += incr;
if (o && o->refcount == 1 && o->encoding == OBJ_ENCODING_INT &&
(value < 0 || value >= OBJ_SHARED_INTEGERS) &&
value >= LONG_MIN && value <= LONG_MAX)
{
new = o;
o->ptr = (void*)((long)value);
} else {
new = createStringObjectFromLongLongForValue(value);
if (o) {
dbOverwrite(c->db,c->argv[1],new);
} else {
dbAdd(c->db,c->argv[1],new);
}
}
signalModifiedKey(c,c->db,c->argv[1]);
notifyKeyspaceEvent(NOTIFY_STRING,"incrby",c->argv[1],c->db->id);
server.dirty++;
addReplyLongLong(c, value);
}
void incrCommand(client *c) {
incrDecrCommand(c,1);
}
void decrCommand(client *c) {
incrDecrCommand(c,-1);
}
void incrbyCommand(client *c) {
long long incr;
if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != C_OK) return;
incrDecrCommand(c,incr);
}
void decrbyCommand(client *c) {
long long incr;
if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != C_OK) return;
/* Overflow check: negating LLONG_MIN will cause an overflow */
if (incr == LLONG_MIN) {
addReplyError(c, "decrement would overflow");
return;
}
incrDecrCommand(c,-incr);
}
void incrbyfloatCommand(client *c) {
long double incr, value;
robj *o, *new;
o = lookupKeyWrite(c->db,c->argv[1]);
if (checkType(c,o,OBJ_STRING)) return;
if (getLongDoubleFromObjectOrReply(c,o,&value,NULL) != C_OK ||
getLongDoubleFromObjectOrReply(c,c->argv[2],&incr,NULL) != C_OK)
return;
value += incr;
if (isnan(value) || isinf(value)) {
addReplyError(c,"increment would produce NaN or Infinity");
return;
}
new = createStringObjectFromLongDouble(value,1);
if (o)
dbOverwrite(c->db,c->argv[1],new);
else
dbAdd(c->db,c->argv[1],new);
signalModifiedKey(c,c->db,c->argv[1]);
notifyKeyspaceEvent(NOTIFY_STRING,"incrbyfloat",c->argv[1],c->db->id);
server.dirty++;
addReplyBulk(c,new);
/* Always replicate INCRBYFLOAT as a SET command with the final value
* in order to make sure that differences in float precision or formatting
* will not create differences in replicas or after an AOF restart. */
rewriteClientCommandArgument(c,0,shared.set);
rewriteClientCommandArgument(c,2,new);
rewriteClientCommandArgument(c,3,shared.keepttl);
}
void appendCommand(client *c) {
size_t totlen;
robj *o, *append;
o = lookupKeyWrite(c->db,c->argv[1]);
if (o == NULL) {
/* Create the key */
c->argv[2] = tryObjectEncoding(c->argv[2]);
dbAdd(c->db,c->argv[1],c->argv[2]);
incrRefCount(c->argv[2]);
totlen = stringObjectLen(c->argv[2]);
} else {
/* Key exists, check type */
if (checkType(c,o,OBJ_STRING))
return;
/* "append" is an argument, so always an sds */
append = c->argv[2];
totlen = stringObjectLen(o)+sdslen(append->ptr);
if (checkStringLength(c,totlen) != C_OK)
return;
/* Append the value */
o = dbUnshareStringValue(c->db,c->argv[1],o);
o->ptr = sdscatlen(o->ptr,append->ptr,sdslen(append->ptr));
totlen = sdslen(o->ptr);
}
signalModifiedKey(c,c->db,c->argv[1]);
notifyKeyspaceEvent(NOTIFY_STRING,"append",c->argv[1],c->db->id);
server.dirty++;
addReplyLongLong(c,totlen);
}
void strlenCommand(client *c) {
robj *o;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,o,OBJ_STRING)) return;
addReplyLongLong(c,stringObjectLen(o));
}
/* LCS key1 key2 [LEN] [IDX] [MINMATCHLEN <len>] [WITHMATCHLEN] */
void lcsCommand(client *c) {
uint32_t i, j;
long long minmatchlen = 0;
sds a = NULL, b = NULL;
int getlen = 0, getidx = 0, withmatchlen = 0;
robj *obja = NULL, *objb = NULL;
obja = lookupKeyRead(c->db,c->argv[1]);
objb = lookupKeyRead(c->db,c->argv[2]);
if ((obja && obja->type != OBJ_STRING) ||
(objb && objb->type != OBJ_STRING))
{
addReplyError(c,
"The specified keys must contain string values");
/* Don't cleanup the objects, we need to do that
* only after calling getDecodedObject(). */
obja = NULL;
objb = NULL;
goto cleanup;
}
obja = obja ? getDecodedObject(obja) : createStringObject("",0);
objb = objb ? getDecodedObject(objb) : createStringObject("",0);
a = obja->ptr;
b = objb->ptr;
for (j = 3; j < (uint32_t)c->argc; j++) {
char *opt = c->argv[j]->ptr;
int moreargs = (c->argc-1) - j;
if (!strcasecmp(opt,"IDX")) {
getidx = 1;
} else if (!strcasecmp(opt,"LEN")) {
getlen = 1;
} else if (!strcasecmp(opt,"WITHMATCHLEN")) {
withmatchlen = 1;
} else if (!strcasecmp(opt,"MINMATCHLEN") && moreargs) {
if (getLongLongFromObjectOrReply(c,c->argv[j+1],&minmatchlen,NULL)
!= C_OK) goto cleanup;
if (minmatchlen < 0) minmatchlen = 0;
j++;
} else {
addReplyErrorObject(c,shared.syntaxerr);
goto cleanup;
}
}
/* Complain if the user passed ambiguous parameters. */
if (getlen && getidx) {
addReplyError(c,
"If you want both the length and indexes, please just use IDX.");
goto cleanup;
}
/* Detect string truncation or later overflows. */
if (sdslen(a) >= UINT32_MAX-1 || sdslen(b) >= UINT32_MAX-1) {
addReplyError(c, "String too long for LCS");
goto cleanup;
}
/* Compute the LCS using the vanilla dynamic programming technique of
* building a table of LCS(x,y) substrings. */
uint32_t alen = sdslen(a);
uint32_t blen = sdslen(b);
/* Setup an uint32_t array to store at LCS[i,j] the length of the
* LCS A0..i-1, B0..j-1. Note that we have a linear array here, so
* we index it as LCS[j+(blen+1)*i] */
#define LCS(A,B) lcs[(B)+((A)*(blen+1))]
/* Try to allocate the LCS table, and abort on overflow or insufficient memory. */
unsigned long long lcssize = (unsigned long long)(alen+1)*(blen+1); /* Can't overflow due to the size limits above. */
unsigned long long lcsalloc = lcssize * sizeof(uint32_t);
uint32_t *lcs = NULL;
if (lcsalloc < SIZE_MAX && lcsalloc / lcssize == sizeof(uint32_t)) {
if (lcsalloc > (size_t)server.proto_max_bulk_len) {
addReplyError(c, "Insufficient memory, transient memory for LCS exceeds proto-max-bulk-len");
goto cleanup;
}
lcs = ztrymalloc(lcsalloc);
}
if (!lcs) {
addReplyError(c, "Insufficient memory, failed allocating transient memory for LCS");
goto cleanup;
}
/* Start building the LCS table. */
for (uint32_t i = 0; i <= alen; i++) {
for (uint32_t j = 0; j <= blen; j++) {
if (i == 0 || j == 0) {
/* If one substring has length of zero, the
* LCS length is zero. */
LCS(i,j) = 0;
} else if (a[i-1] == b[j-1]) {
/* The len LCS (and the LCS itself) of two
* sequences with the same final character, is the
* LCS of the two sequences without the last char
* plus that last char. */
LCS(i,j) = LCS(i-1,j-1)+1;
} else {
/* If the last character is different, take the longest
* between the LCS of the first string and the second
* minus the last char, and the reverse. */
uint32_t lcs1 = LCS(i-1,j);
uint32_t lcs2 = LCS(i,j-1);
LCS(i,j) = lcs1 > lcs2 ? lcs1 : lcs2;
}
}
}
/* Store the actual LCS string in "result" if needed. We create
* it backward, but the length is already known, we store it into idx. */
uint32_t idx = LCS(alen,blen);
sds result = NULL; /* Resulting LCS string. */
void *arraylenptr = NULL; /* Deferred length of the array for IDX. */
uint32_t arange_start = alen, /* alen signals that values are not set. */
arange_end = 0,
brange_start = 0,
brange_end = 0;
/* Do we need to compute the actual LCS string? Allocate it in that case. */
int computelcs = getidx || !getlen;
if (computelcs) result = sdsnewlen(SDS_NOINIT,idx);
/* Start with a deferred array if we have to emit the ranges. */
uint32_t arraylen = 0; /* Number of ranges emitted in the array. */
if (getidx) {
addReplyMapLen(c,2);
addReplyBulkCString(c,"matches");
arraylenptr = addReplyDeferredLen(c);
}
i = alen, j = blen;
while (computelcs && i > 0 && j > 0) {
int emit_range = 0;
if (a[i-1] == b[j-1]) {
/* If there is a match, store the character and reduce
* the indexes to look for a new match. */
result[idx-1] = a[i-1];
/* Track the current range. */
if (arange_start == alen) {
arange_start = i-1;
arange_end = i-1;
brange_start = j-1;
brange_end = j-1;
} else {
/* Let's see if we can extend the range backward since
* it is contiguous. */
if (arange_start == i && brange_start == j) {
arange_start--;
brange_start--;
} else {
emit_range = 1;
}
}
/* Emit the range if we matched with the first byte of
* one of the two strings. We'll exit the loop ASAP. */
if (arange_start == 0 || brange_start == 0) emit_range = 1;
idx--; i--; j--;
} else {
/* Otherwise reduce i and j depending on the largest
* LCS between, to understand what direction we need to go. */
uint32_t lcs1 = LCS(i-1,j);
uint32_t lcs2 = LCS(i,j-1);
if (lcs1 > lcs2)
i--;
else
j--;
if (arange_start != alen) emit_range = 1;
}
/* Emit the current range if needed. */
uint32_t match_len = arange_end - arange_start + 1;
if (emit_range) {
if (minmatchlen == 0 || match_len >= minmatchlen) {
if (arraylenptr) {
addReplyArrayLen(c,2+withmatchlen);
addReplyArrayLen(c,2);
addReplyLongLong(c,arange_start);
addReplyLongLong(c,arange_end);
addReplyArrayLen(c,2);
addReplyLongLong(c,brange_start);
addReplyLongLong(c,brange_end);
if (withmatchlen) addReplyLongLong(c,match_len);
arraylen++;
}
}
arange_start = alen; /* Restart at the next match. */
}
}
/* Signal modified key, increment dirty, ... */
/* Reply depending on the given options. */
if (arraylenptr) {
addReplyBulkCString(c,"len");
addReplyLongLong(c,LCS(alen,blen));
setDeferredArrayLen(c,arraylenptr,arraylen);
} else if (getlen) {
addReplyLongLong(c,LCS(alen,blen));
} else {
addReplyBulkSds(c,result);
result = NULL;
}
/* Cleanup. */
sdsfree(result);
zfree(lcs);
cleanup:
if (obja) decrRefCount(obja);
if (objb) decrRefCount(objb);
return;
}
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