Skip to content

Commit

Permalink
Use pre-allocated buffer for error strings in reader
Browse files Browse the repository at this point in the history
  • Loading branch information
@pietern
pietern committed Apr 20, 2011
1 parent 5d78214 commit eaf58bd
Show file tree
Hide file tree
Showing 3 changed files with 116 additions and 67 deletions.
149 changes: 86 additions & 63 deletions hiredis.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -41,13 +41,10 @@
#include "sds.h"
#include "util.h"

#define REDIS_READER_OOM -2
#define REDIS_READER_NEED_MORE_DATA -1
#define REDIS_READER_OK 0

typedef struct redisReader {
int err; /* Error flags, 0 when there is no error */
char errstr[128]; /* String representation of error when applicable */
struct redisReplyObjectFunctions *fn;
sds error; /* holds optional error */
void *reply; /* holds temporary reply */

sds buf; /* read buffer */
Expand All @@ -64,7 +61,6 @@ static void *createStringObject(const redisReadTask *task, char *str, size_t len
static void *createArrayObject(const redisReadTask *task, int elements);
static void *createIntegerObject(const redisReadTask *task, long long value);
static void *createNilObject(const redisReadTask *task);
static void redisSetReplyReaderError(redisReader *r, sds err);

/* Default set of functions to build the reply. Keep in mind that such a
* function returning NULL is interpreted as OOM. */
Expand Down Expand Up @@ -200,6 +196,45 @@ static void *createNilObject(const redisReadTask *task) {
return r;
}

static void __redisReplyReaderSetError(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 void __redisReplyReaderSetErrorProtocolByte(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);
__redisReplyReaderSetError(r,REDIS_ERR_PROTOCOL,sbuf);
}

static void __redisReplyReaderSetErrorOOM(redisReader *r) {
__redisReplyReaderSetError(r,REDIS_ERR_OOM,"Out of memory");
}

static char *readBytes(redisReader *r, unsigned int bytes) {
char *p;
if (r->len-r->pos >= bytes) {
Expand Down Expand Up @@ -326,16 +361,18 @@ static int processLineItem(redisReader *r) {
obj = (void*)(size_t)(cur->type);
}

if (obj == NULL)
return REDIS_READER_OOM;
if (obj == NULL) {
__redisReplyReaderSetErrorOOM(r);
return REDIS_ERR;
}

/* Set reply if this is the root object. */
if (r->ridx == 0) r->reply = obj;
moveToNextTask(r);
return REDIS_READER_OK;
return REDIS_OK;
}

return REDIS_READER_NEED_MORE_DATA;
return REDIS_ERR;
}

static int processBulkItem(redisReader *r) {
Expand Down Expand Up @@ -374,19 +411,21 @@ static int processBulkItem(redisReader *r) {

/* Proceed when obj was created. */
if (success) {
if (obj == NULL)
return REDIS_READER_OOM;
if (obj == NULL) {
__redisReplyReaderSetErrorOOM(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_READER_OK;
return REDIS_OK;
}
}

return REDIS_READER_NEED_MORE_DATA;
return REDIS_ERR;
}

static int processMultiBulkItem(redisReader *r) {
Expand All @@ -398,9 +437,9 @@ static int processMultiBulkItem(redisReader *r) {

/* Set error for nested multi bulks with depth > 1 */
if (r->ridx == 2) {
redisSetReplyReaderError(r,sdscatprintf(sdsempty(),
"No support for nested multi bulk replies with depth > 1"));
return -1;
__redisReplyReaderSetError(r,REDIS_ERR_PROTOCOL,
"No support for nested multi bulk replies with depth > 1");
return REDIS_ERR;
}

if ((p = readLine(r,NULL)) != NULL) {
Expand All @@ -413,8 +452,10 @@ static int processMultiBulkItem(redisReader *r) {
else
obj = (void*)REDIS_REPLY_NIL;

if (obj == NULL)
return REDIS_READER_OOM;
if (obj == NULL) {
__redisReplyReaderSetErrorOOM(r);
return REDIS_ERR;
}

moveToNextTask(r);
} else {
Expand All @@ -423,8 +464,10 @@ static int processMultiBulkItem(redisReader *r) {
else
obj = (void*)REDIS_REPLY_ARRAY;

if (obj == NULL)
return REDIS_READER_OOM;
if (obj == NULL) {
__redisReplyReaderSetErrorOOM(r);
return REDIS_ERR;
}

/* Modify task stack when there are more than 0 elements. */
if (elements > 0) {
Expand All @@ -444,16 +487,15 @@ static int processMultiBulkItem(redisReader *r) {

/* Set reply if this is the root object. */
if (root) r->reply = obj;
return REDIS_READER_OK;
return REDIS_OK;
}

return REDIS_READER_NEED_MORE_DATA;
return REDIS_ERR;
}

static int processItem(redisReader *r) {
redisReadTask *cur = &(r->rstack[r->ridx]);
char *p;
sds byte;

/* check if we need to read type */
if (cur->type < 0) {
Expand All @@ -475,15 +517,12 @@ static int processItem(redisReader *r) {
cur->type = REDIS_REPLY_ARRAY;
break;
default:
byte = sdscatrepr(sdsempty(),p,1);
redisSetReplyReaderError(r,sdscatprintf(sdsempty(),
"Protocol error, got %s as reply type byte", byte));
sdsfree(byte);
return -1;
__redisReplyReaderSetErrorProtocolByte(r,*p);
return REDIS_ERR;
}
} else {
/* could not consume 1 byte */
return -1;
return REDIS_ERR;
}
}

Expand All @@ -499,13 +538,14 @@ static int processItem(redisReader *r) {
return processMultiBulkItem(r);
default:
assert(NULL);
return -1;
return REDIS_ERR; /* Avoid warning. */
}
}

void *redisReplyReaderCreate(void) {
redisReader *r = calloc(sizeof(redisReader),1);
r->error = NULL;
r->err = 0;
r->errstr[0] = '\0';
r->fn = &defaultFunctions;
r->buf = sdsempty();
r->ridx = -1;
Expand Down Expand Up @@ -545,32 +585,16 @@ void *redisReplyReaderGetObject(void *reader) {

void redisReplyReaderFree(void *reader) {
redisReader *r = reader;
if (r->error != NULL)
sdsfree(r->error);
if (r->reply != NULL && r->fn)
r->fn->freeObject(r->reply);
if (r->buf != NULL)
sdsfree(r->buf);
free(r);
}

static void redisSetReplyReaderError(redisReader *r, sds err) {
if (r->reply != NULL)
r->fn->freeObject(r->reply);

/* Clear remaining buffer when we see a protocol error. */
if (r->buf != NULL) {
sdsfree(r->buf);
r->buf = sdsempty();
r->pos = r->len = 0;
}
r->ridx = -1;
r->error = err;
}

char *redisReplyReaderGetError(void *reader) {
redisReader *r = reader;
return r->error;
return r->errstr;
}

void redisReplyReaderFeed(void *reader, const char *buf, size_t len) {
Expand All @@ -592,9 +616,14 @@ void redisReplyReaderFeed(void *reader, const char *buf, size_t len) {

int redisReplyReaderGetReply(void *reader, void **reply) {
redisReader *r = reader;
int ret = REDIS_READER_OK;

if (reply != NULL) *reply = NULL;
/* 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)
Expand All @@ -613,11 +642,11 @@ int redisReplyReaderGetReply(void *reader, void **reply) {

/* Process items in reply. */
while (r->ridx >= 0)
if ((ret = processItem(r)) != REDIS_READER_OK)
if (processItem(r) != REDIS_OK)
break;

/* Set errors on OOM. */
if (ret == REDIS_READER_OOM)
/* 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
Expand All @@ -630,15 +659,9 @@ int redisReplyReaderGetReply(void *reader, void **reply) {

/* Emit a reply when there is one. */
if (r->ridx == -1) {
void *aux = r->reply;
if (reply != NULL)
*reply = r->reply;
r->reply = NULL;

/* Check if there actually *is* a reply. */
if (r->error != NULL) {
return REDIS_ERR;
} else {
if (reply != NULL) *reply = aux;
}
}
return REDIS_OK;
}
Expand Down Expand Up @@ -1024,7 +1047,7 @@ int redisGetReplyFromReader(redisContext *c, void **reply) {
__redisCreateReplyReader(c);
if (redisReplyReaderGetReply(c->reader,reply) == REDIS_ERR) {
__redisSetError(c,REDIS_ERR_PROTOCOL,
sdsnew(((redisReader*)c->reader)->error));
sdsnew(((redisReader*)c->reader)->errstr));
return REDIS_ERR;
}
return REDIS_OK;
Expand Down
9 changes: 5 additions & 4 deletions hiredis.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -46,10 +46,11 @@
* error that occured. REDIS_ERR_IO means there was an I/O error and you
* should use the "errno" variable to find out what is wrong.
* For other values, the "errstr" field will hold a description. */
#define REDIS_ERR_IO 1 /* error in read or write */
#define REDIS_ERR_EOF 3 /* eof */
#define REDIS_ERR_PROTOCOL 4 /* protocol error */
#define REDIS_ERR_OTHER 2 /* something else */
#define REDIS_ERR_IO 1 /* Error in read or write */
#define REDIS_ERR_EOF 3 /* End of file */
#define REDIS_ERR_PROTOCOL 4 /* Protocol error */
#define REDIS_ERR_OOM 5 /* Out of memory */
#define REDIS_ERR_OTHER 2 /* Everything else... */

/* Connection type can be blocking or non-blocking and is set in the
* least significant bit of the flags field in redisContext. */
Expand Down
25 changes: 25 additions & 0 deletions util.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,11 +30,36 @@
#ifndef __UTIL_H
#define __UTIL_H
#include <stdlib.h>
#include <stdio.h>

/* Abort on out of memory */
static void redisOOM(void) {
fprintf(stderr,"Out of memory in hiredis");
exit(1);
}

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;
}

#endif

0 comments on commit eaf58bd

Please sign in to comment.