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Diffstat (limited to 'src/t_string.c')
| -rw-r--r-- | src/t_string.c | 951 |
1 files changed, 951 insertions, 0 deletions
diff --git a/src/t_string.c b/src/t_string.c new file mode 100644 index 0000000..2bce3ac --- /dev/null +++ b/src/t_string.c @@ -0,0 +1,951 @@ +/* + * 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, long long append) { + if (mustObeyClient(c)) + return C_OK; + /* 'uint64_t' cast is there just to prevent undefined behavior on overflow */ + long long total = (uint64_t)size + append; + /* Test configured max-bulk-len represending a limit of the biggest string object, + * and also test for overflow. */ + if (total > server.proto_max_bulk_len || total < size || total < append) { + 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; + } + + /* When expire is not NULL, we avoid deleting the TTL so it can be updated later instead of being deleted and then created again. */ + setkey_flags |= ((flags & OBJ_KEEPTTL) || expire) ? 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 flag. */ + if (!(flags & OBJ_PXAT)) { + 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 += commandTimeSnapshot(); + } + + 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 = dbGenericDelete(c->db, c->argv[1], server.lazyfree_lazy_expire, DB_FLAG_KEY_EXPIRED); + 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; + if (dbSyncDelete(c->db, c->argv[1])) { + /* Propagate as DEL command */ + rewriteClientCommandVector(c,2,shared.del,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; + } + } + } + + int setkey_flags = nx ? SETKEY_DOESNT_EXIST : 0; + 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], setkey_flags); + notifyKeyspaceEvent(NOTIFY_STRING,"set",c->argv[j],c->db->id); + /* In MSETNX, It could be that we're overriding the same key, we can't be sure it doesn't exist. */ + if (nx) + setkey_flags = SETKEY_ADD_OR_UPDATE; + } + 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) { + dbReplaceValue(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) + dbReplaceValue(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]; + if (checkStringLength(c,stringObjectLen(o),sdslen(append->ptr)) != 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; +} + |