zeekling/hiredis
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Use a fixed size stack instead of a dynamic list for read tasks

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This commit is contained in:
Pieter Noordhuis 2010-10-31 14:42:48 +01:00
parent 8a80b89232
commit 3f0394b8a9
2 changed files with 60 additions and 52 deletions
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105
hiredis.c
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@ -47,9 +47,8 @@ typedef struct redisReader {
sds buf; /* read buffer */
unsigned int pos; /* buffer cursor */
redisReadTask *rlist; /* list of items to process */
unsigned int rlen; /* list length */
unsigned int rpos; /* list cursor */
redisReadTask rstack[3]; /* stack of read tasks */
int ridx; /* index of stack */
} redisReader;
static redisReply *createReplyObject(int type);
@ -183,8 +182,33 @@ static char *readLine(redisReader *r, int *_len) {
return NULL;
}
static void moveToNextTask(redisReader *r) {
redisReadTask *cur, *prv;
assert(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--;
moveToNextTask(r);
} else {
/* Reset the type because the next item can be anything */
assert(cur->idx < prv->elements);
cur->type = -1;
cur->elements = -1;
cur->idx++;
}
}
static int processLineItem(redisReader *r) {
redisReadTask *cur = &(r->rlist[r->rpos]);
redisReadTask *cur = &(r->rstack[r->ridx]);
void *obj;
char *p;
int len;
@ -199,14 +223,14 @@ static int processLineItem(redisReader *r) {
/* If there is no root yet, register this object as root. */
if (r->reply == NULL)
r->reply = obj;
r->rpos++;
moveToNextTask(r);
return 0;
}
return -1;
}
static int processBulkItem(redisReader *r) {
redisReadTask *cur = &(r->rlist[r->rpos]);
redisReadTask *cur = &(r->rstack[r->ridx]);
void *obj = NULL;
char *p, *s;
long len;
@ -235,7 +259,7 @@ static int processBulkItem(redisReader *r) {
r->pos += bytelen;
if (r->reply == NULL)
r->reply = obj;
r->rpos++;
moveToNextTask(r);
return 0;
}
}
@ -243,53 +267,42 @@ static int processBulkItem(redisReader *r) {
}
static int processMultiBulkItem(redisReader *r) {
redisReadTask *cur = &(r->rlist[r->rpos]);
redisReadTask *cur = &(r->rstack[r->ridx]);
void *obj;
char *p;
long elements, j;
long elements;
if ((p = readLine(r,NULL)) != NULL) {
elements = strtol(p,NULL,10);
if (elements == -1) {
obj = r->fn->createNil(cur);
moveToNextTask(r);
} else {
obj = r->fn->createArray(cur,elements);
/* Modify read list when there are more than 0 elements. */
/* Modify task stack when there are more than 0 elements. */
if (elements > 0) {
/* Append elements to the read list. */
r->rlen += elements;
if ((r->rlist = realloc(r->rlist,sizeof(redisReadTask)*r->rlen)) == NULL)
redisOOM();
/* Move existing items backwards. */
memmove(&(r->rlist[r->rpos+1+elements]),
&(r->rlist[r->rpos+1]),
(r->rlen-(r->rpos+1+elements))*sizeof(redisReadTask));
/* Populate new read items. */
redisReadTask *t;
for (j = 0; j < elements; j++) {
t = &(r->rlist[r->rpos+1+j]);
t->type = -1;
t->parent = obj;
t->idx = j;
}
cur->elements = elements;
r->ridx++;
r->rstack[r->ridx].type = -1;
r->rstack[r->ridx].elements = -1;
r->rstack[r->ridx].parent = obj;
r->rstack[r->ridx].idx = 0;
} else {
moveToNextTask(r);
}
}
if (obj != NULL) {
/* Object was created, so we can always continue. */
if (r->reply == NULL)
r->reply = obj;
r->rpos++;
return 0;
}
}
return -1;
}
static int processItem(redisReader *r) {
redisReadTask *cur = &(r->rlist[r->rpos]);
redisReadTask *cur = &(r->rstack[r->ridx]);
char *p;
sds byte;
@ -347,7 +360,7 @@ void *redisReplyReaderCreate(redisReplyObjectFunctions *fn) {
r->error = NULL;
r->fn = fn == NULL ? &defaultFunctions : fn;
r->buf = sdsempty();
r->rlist = malloc(sizeof(redisReadTask)*1);
r->ridx = -1;
return r;
}
@ -368,8 +381,6 @@ void redisReplyReaderFree(void *reader) {
r->fn->freeObject(r->reply);
if (r->buf != NULL)
sdsfree(r->buf);
if (r->rlist != NULL)
free(r->rlist);
free(r);
}
@ -383,7 +394,7 @@ static void redisSetReplyReaderError(redisReader *r, sds err) {
r->buf = sdsempty();
r->pos = 0;
}
r->rlen = r->rpos = 0;
r->ridx = -1;
r->error = err;
}
@ -408,18 +419,17 @@ int redisReplyReaderGetReply(void *reader, void **reply) {
if (sdslen(r->buf) == 0)
return REDIS_OK;
/* Create first item to process when the item list is empty. */
if (r->rlen == 0) {
r->rlist = realloc(r->rlist,sizeof(redisReadTask)*1);
r->rlist[0].type = -1;
r->rlist[0].parent = NULL;
r->rlist[0].idx = -1;
r->rlen = 1;
r->rpos = 0;
/* 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].parent = NULL;
r->rstack[0].idx = -1;
r->ridx = 0;
}
/* Process items in reply. */
while (r->rpos < r->rlen)
while (r->ridx >= 0)
if (processItem(r) < 0)
break;
@ -436,7 +446,7 @@ int redisReplyReaderGetReply(void *reader, void **reply) {
}
/* Emit a reply when there is one. */
if (r->rpos == r->rlen) {
if (r->ridx == -1) {
void *aux = r->reply;
r->reply = NULL;
@ -447,9 +457,6 @@ int redisReplyReaderGetReply(void *reader, void **reply) {
r->pos = 0;
}
/* Set list of items to read to be empty. */
r->rlen = r->rpos = 0;
/* Check if there actually *is* a reply. */
if (r->error != NULL) {
return REDIS_ERR;

1
hiredis.h
View File

@ -61,6 +61,7 @@ typedef struct redisReply {
typedef struct redisReadTask {
int type;
int elements; /* number of elements in multibulk container */
void *parent; /* optional pointer to parent object */
int idx; /* index in parent (array) object */
} redisReadTask;