diff options
Diffstat (limited to 'read.c')
| -rw-r--r-- | read.c | 523 |
1 files changed, 523 insertions, 0 deletions
@@ -0,0 +1,523 @@ +/* + * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com> + * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis 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 "fmacros.h" +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <assert.h> +#include <errno.h> +#include <ctype.h> + +#include "read.h" +#include "sds.h" + +static void __redisReaderSetError(redisReader *r, int type, const char *str) { + size_t len; + + if (r->reply != NULL && r->fn && r->fn->freeObject) { + r->fn->freeObject(r->reply); + r->reply = NULL; + } + + /* Clear input buffer on errors. */ + if (r->buf != NULL) { + sdsfree(r->buf); + r->buf = NULL; + r->pos = r->len = 0; + } + + /* Reset task stack. */ + r->ridx = -1; + + /* Set error. */ + r->err = type; + len = strlen(str); + len = len < (sizeof(r->errstr)-1) ? len : (sizeof(r->errstr)-1); + memcpy(r->errstr,str,len); + r->errstr[len] = '\0'; +} + +static size_t chrtos(char *buf, size_t size, char byte) { + size_t len = 0; + + switch(byte) { + case '\\': + case '"': + len = snprintf(buf,size,"\"\\%c\"",byte); + break; + case '\n': len = snprintf(buf,size,"\"\\n\""); break; + case '\r': len = snprintf(buf,size,"\"\\r\""); break; + case '\t': len = snprintf(buf,size,"\"\\t\""); break; + case '\a': len = snprintf(buf,size,"\"\\a\""); break; + case '\b': len = snprintf(buf,size,"\"\\b\""); break; + default: + if (isprint(byte)) + len = snprintf(buf,size,"\"%c\"",byte); + else + len = snprintf(buf,size,"\"\\x%02x\"",(unsigned char)byte); + break; + } + + return len; +} + +static void __redisReaderSetErrorProtocolByte(redisReader *r, char byte) { + char cbuf[8], sbuf[128]; + + chrtos(cbuf,sizeof(cbuf),byte); + snprintf(sbuf,sizeof(sbuf), + "Protocol error, got %s as reply type byte", cbuf); + __redisReaderSetError(r,REDIS_ERR_PROTOCOL,sbuf); +} + +static void __redisReaderSetErrorOOM(redisReader *r) { + __redisReaderSetError(r,REDIS_ERR_OOM,"Out of memory"); +} + +static char *readBytes(redisReader *r, unsigned int bytes) { + char *p; + if (r->len-r->pos >= bytes) { + p = r->buf+r->pos; + r->pos += bytes; + return p; + } + return NULL; +} + +/* Find pointer to \r\n. */ +static char *seekNewline(char *s, size_t len) { + int pos = 0; + int _len = len-1; + + /* Position should be < len-1 because the character at "pos" should be + * followed by a \n. Note that strchr cannot be used because it doesn't + * allow to search a limited length and the buffer that is being searched + * might not have a trailing NULL character. */ + while (pos < _len) { + while(pos < _len && s[pos] != '\r') pos++; + if (s[pos] != '\r') { + /* Not found. */ + return NULL; + } else { + if (s[pos+1] == '\n') { + /* Found. */ + return s+pos; + } else { + /* Continue searching. */ + pos++; + } + } + } + return NULL; +} + +/* Read a long long value starting at *s, under the assumption that it will be + * terminated by \r\n. Ambiguously returns -1 for unexpected input. */ +static long long readLongLong(char *s) { + long long v = 0; + int dec, mult = 1; + char c; + + if (*s == '-') { + mult = -1; + s++; + } else if (*s == '+') { + mult = 1; + s++; + } + + while ((c = *(s++)) != '\r') { + dec = c - '0'; + if (dec >= 0 && dec < 10) { + v *= 10; + v += dec; + } else { + /* Should not happen... */ + return -1; + } + } + + return mult*v; +} + +static char *readLine(redisReader *r, int *_len) { + char *p, *s; + int len; + + p = r->buf+r->pos; + s = seekNewline(p,(r->len-r->pos)); + if (s != NULL) { + len = s-(r->buf+r->pos); + r->pos += len+2; /* skip \r\n */ + if (_len) *_len = len; + return p; + } + return NULL; +} + +static void moveToNextTask(redisReader *r) { + redisReadTask *cur, *prv; + while (r->ridx >= 0) { + /* Return a.s.a.p. when the stack is now empty. */ + if (r->ridx == 0) { + r->ridx--; + return; + } + + cur = &(r->rstack[r->ridx]); + prv = &(r->rstack[r->ridx-1]); + assert(prv->type == REDIS_REPLY_ARRAY); + if (cur->idx == prv->elements-1) { + r->ridx--; + } else { + /* Reset the type because the next item can be anything */ + assert(cur->idx < prv->elements); + cur->type = -1; + cur->elements = -1; + cur->idx++; + return; + } + } +} + +static int processLineItem(redisReader *r) { + redisReadTask *cur = &(r->rstack[r->ridx]); + void *obj; + char *p; + int len; + + if ((p = readLine(r,&len)) != NULL) { + if (cur->type == REDIS_REPLY_INTEGER) { + if (r->fn && r->fn->createInteger) + obj = r->fn->createInteger(cur,readLongLong(p)); + else + obj = (void*)REDIS_REPLY_INTEGER; + } else { + /* Type will be error or status. */ + if (r->fn && r->fn->createString) + obj = r->fn->createString(cur,p,len); + else + obj = (void*)(size_t)(cur->type); + } + + if (obj == NULL) { + __redisReaderSetErrorOOM(r); + return REDIS_ERR; + } + + /* Set reply if this is the root object. */ + if (r->ridx == 0) r->reply = obj; + moveToNextTask(r); + return REDIS_OK; + } + + return REDIS_ERR; +} + +static int processBulkItem(redisReader *r) { + redisReadTask *cur = &(r->rstack[r->ridx]); + void *obj = NULL; + char *p, *s; + long len; + unsigned long bytelen; + int success = 0; + + p = r->buf+r->pos; + s = seekNewline(p,r->len-r->pos); + if (s != NULL) { + p = r->buf+r->pos; + bytelen = s-(r->buf+r->pos)+2; /* include \r\n */ + len = readLongLong(p); + + if (len < 0) { + /* The nil object can always be created. */ + if (r->fn && r->fn->createNil) + obj = r->fn->createNil(cur); + else + obj = (void*)REDIS_REPLY_NIL; + success = 1; + } else { + /* Only continue when the buffer contains the entire bulk item. */ + bytelen += len+2; /* include \r\n */ + if (r->pos+bytelen <= r->len) { + if (r->fn && r->fn->createString) + obj = r->fn->createString(cur,s+2,len); + else + obj = (void*)REDIS_REPLY_STRING; + success = 1; + } + } + + /* Proceed when obj was created. */ + if (success) { + if (obj == NULL) { + __redisReaderSetErrorOOM(r); + return REDIS_ERR; + } + + r->pos += bytelen; + + /* Set reply if this is the root object. */ + if (r->ridx == 0) r->reply = obj; + moveToNextTask(r); + return REDIS_OK; + } + } + + return REDIS_ERR; +} + +static int processMultiBulkItem(redisReader *r) { + redisReadTask *cur = &(r->rstack[r->ridx]); + void *obj; + char *p; + long elements; + int root = 0; + + /* Set error for nested multi bulks with depth > 7 */ + if (r->ridx == 8) { + __redisReaderSetError(r,REDIS_ERR_PROTOCOL, + "No support for nested multi bulk replies with depth > 7"); + return REDIS_ERR; + } + + if ((p = readLine(r,NULL)) != NULL) { + elements = readLongLong(p); + root = (r->ridx == 0); + + if (elements == -1) { + if (r->fn && r->fn->createNil) + obj = r->fn->createNil(cur); + else + obj = (void*)REDIS_REPLY_NIL; + + if (obj == NULL) { + __redisReaderSetErrorOOM(r); + return REDIS_ERR; + } + + moveToNextTask(r); + } else { + if (r->fn && r->fn->createArray) + obj = r->fn->createArray(cur,elements); + else + obj = (void*)REDIS_REPLY_ARRAY; + + if (obj == NULL) { + __redisReaderSetErrorOOM(r); + return REDIS_ERR; + } + + /* Modify task stack when there are more than 0 elements. */ + if (elements > 0) { + cur->elements = elements; + cur->obj = obj; + r->ridx++; + r->rstack[r->ridx].type = -1; + r->rstack[r->ridx].elements = -1; + r->rstack[r->ridx].idx = 0; + r->rstack[r->ridx].obj = NULL; + r->rstack[r->ridx].parent = cur; + r->rstack[r->ridx].privdata = r->privdata; + } else { + moveToNextTask(r); + } + } + + /* Set reply if this is the root object. */ + if (root) r->reply = obj; + return REDIS_OK; + } + + return REDIS_ERR; +} + +static int processItem(redisReader *r) { + redisReadTask *cur = &(r->rstack[r->ridx]); + char *p; + + /* check if we need to read type */ + if (cur->type < 0) { + if ((p = readBytes(r,1)) != NULL) { + switch (p[0]) { + case '-': + cur->type = REDIS_REPLY_ERROR; + break; + case '+': + cur->type = REDIS_REPLY_STATUS; + break; + case ':': + cur->type = REDIS_REPLY_INTEGER; + break; + case '$': + cur->type = REDIS_REPLY_STRING; + break; + case '*': + cur->type = REDIS_REPLY_ARRAY; + break; + default: + __redisReaderSetErrorProtocolByte(r,*p); + return REDIS_ERR; + } + } else { + /* could not consume 1 byte */ + return REDIS_ERR; + } + } + + /* process typed item */ + switch(cur->type) { + case REDIS_REPLY_ERROR: + case REDIS_REPLY_STATUS: + case REDIS_REPLY_INTEGER: + return processLineItem(r); + case REDIS_REPLY_STRING: + return processBulkItem(r); + case REDIS_REPLY_ARRAY: + return processMultiBulkItem(r); + default: + assert(NULL); + return REDIS_ERR; /* Avoid warning. */ + } +} + +redisReader *redisReaderCreateWithFunctions(redisReplyObjectFunctions *fn) { + redisReader *r; + + r = calloc(sizeof(redisReader),1); + if (r == NULL) + return NULL; + + r->err = 0; + r->errstr[0] = '\0'; + r->fn = fn; + r->buf = sdsempty(); + r->maxbuf = REDIS_READER_MAX_BUF; + if (r->buf == NULL) { + free(r); + return NULL; + } + + r->ridx = -1; + return r; +} + +void redisReaderFree(redisReader *r) { + if (r->reply != NULL && r->fn && r->fn->freeObject) + r->fn->freeObject(r->reply); + if (r->buf != NULL) + sdsfree(r->buf); + free(r); +} + +int redisReaderFeed(redisReader *r, const char *buf, size_t len) { + sds newbuf; + + /* Return early when this reader is in an erroneous state. */ + if (r->err) + return REDIS_ERR; + + /* Copy the provided buffer. */ + if (buf != NULL && len >= 1) { + /* Destroy internal buffer when it is empty and is quite large. */ + if (r->len == 0 && r->maxbuf != 0 && sdsavail(r->buf) > r->maxbuf) { + sdsfree(r->buf); + r->buf = sdsempty(); + r->pos = 0; + + /* r->buf should not be NULL since we just free'd a larger one. */ + assert(r->buf != NULL); + } + + newbuf = sdscatlen(r->buf,buf,len); + if (newbuf == NULL) { + __redisReaderSetErrorOOM(r); + return REDIS_ERR; + } + + r->buf = newbuf; + r->len = sdslen(r->buf); + } + + return REDIS_OK; +} + +int redisReaderGetReply(redisReader *r, void **reply) { + /* Default target pointer to NULL. */ + if (reply != NULL) + *reply = NULL; + + /* Return early when this reader is in an erroneous state. */ + if (r->err) + return REDIS_ERR; + + /* When the buffer is empty, there will never be a reply. */ + if (r->len == 0) + return REDIS_OK; + + /* Set first item to process when the stack is empty. */ + if (r->ridx == -1) { + r->rstack[0].type = -1; + r->rstack[0].elements = -1; + r->rstack[0].idx = -1; + r->rstack[0].obj = NULL; + r->rstack[0].parent = NULL; + r->rstack[0].privdata = r->privdata; + r->ridx = 0; + } + + /* Process items in reply. */ + while (r->ridx >= 0) + if (processItem(r) != REDIS_OK) + break; + + /* Return ASAP when an error occurred. */ + if (r->err) + return REDIS_ERR; + + /* Discard part of the buffer when we've consumed at least 1k, to avoid + * doing unnecessary calls to memmove() in sds.c. */ + if (r->pos >= 1024) { + sdsrange(r->buf,r->pos,-1); + r->pos = 0; + r->len = sdslen(r->buf); + } + + /* Emit a reply when there is one. */ + if (r->ridx == -1) { + if (reply != NULL) + *reply = r->reply; + r->reply = NULL; + } + return REDIS_OK; +} |