hiredis/hiredis.h
Jan-Erik Rediger d9e0b0f6ab Implement a reconnect method for the client context
Originally implemented by @abedra as part of #306.

In case a write or read times out, we force an error state, because we
can't guarantuee that the next read will get the right data.
Instead we need to reconnect to have a clean-state connection, which is
now easily possible with this method.
2015-04-16 21:00:30 +02:00

210 lines
8.9 KiB
C

/*
* 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.
*/
#ifndef __HIREDIS_H
#define __HIREDIS_H
#include "read.h"
#include <stdarg.h> /* for va_list */
#include <sys/time.h> /* for struct timeval */
#include <stdint.h> /* uintXX_t, etc */
#include "sds.h" /* for sds */
#define HIREDIS_MAJOR 0
#define HIREDIS_MINOR 12
#define HIREDIS_PATCH 1
/* Connection type can be blocking or non-blocking and is set in the
* least significant bit of the flags field in redisContext. */
#define REDIS_BLOCK 0x1
/* Connection may be disconnected before being free'd. The second bit
* in the flags field is set when the context is connected. */
#define REDIS_CONNECTED 0x2
/* The async API might try to disconnect cleanly and flush the output
* buffer and read all subsequent replies before disconnecting.
* This flag means no new commands can come in and the connection
* should be terminated once all replies have been read. */
#define REDIS_DISCONNECTING 0x4
/* Flag specific to the async API which means that the context should be clean
* up as soon as possible. */
#define REDIS_FREEING 0x8
/* Flag that is set when an async callback is executed. */
#define REDIS_IN_CALLBACK 0x10
/* Flag that is set when the async context has one or more subscriptions. */
#define REDIS_SUBSCRIBED 0x20
/* Flag that is set when monitor mode is active */
#define REDIS_MONITORING 0x40
/* Flag that is set when we should set SO_REUSEADDR before calling bind() */
#define REDIS_REUSEADDR 0x80
#define REDIS_KEEPALIVE_INTERVAL 15 /* seconds */
/* number of times we retry to connect in the case of EADDRNOTAVAIL and
* SO_REUSEADDR is being used. */
#define REDIS_CONNECT_RETRIES 10
/* strerror_r has two completely different prototypes and behaviors
* depending on system issues, so we need to operate on the error buffer
* differently depending on which strerror_r we're using. */
#ifndef _GNU_SOURCE
/* "regular" POSIX strerror_r that does the right thing. */
#define __redis_strerror_r(errno, buf, len) \
do { \
strerror_r((errno), (buf), (len)); \
} while (0)
#else
/* "bad" GNU strerror_r we need to clean up after. */
#define __redis_strerror_r(errno, buf, len) \
do { \
char *err_str = strerror_r((errno), (buf), (len)); \
/* If return value _isn't_ the start of the buffer we passed in, \
* then GNU strerror_r returned an internal static buffer and we \
* need to copy the result into our private buffer. */ \
if (err_str != (buf)) { \
buf[(len)] = '\0'; \
strncat((buf), err_str, ((len) - 1)); \
} \
} while (0)
#endif
#ifdef __cplusplus
extern "C" {
#endif
/* This is the reply object returned by redisCommand() */
typedef struct redisReply {
int type; /* REDIS_REPLY_* */
long long integer; /* The integer when type is REDIS_REPLY_INTEGER */
int len; /* Length of string */
char *str; /* Used for both REDIS_REPLY_ERROR and REDIS_REPLY_STRING */
size_t elements; /* number of elements, for REDIS_REPLY_ARRAY */
struct redisReply **element; /* elements vector for REDIS_REPLY_ARRAY */
} redisReply;
redisReader *redisReaderCreate(void);
/* Function to free the reply objects hiredis returns by default. */
void freeReplyObject(void *reply);
/* Functions to format a command according to the protocol. */
int redisvFormatCommand(char **target, const char *format, va_list ap);
int redisFormatCommand(char **target, const char *format, ...);
int redisFormatCommandArgv(char **target, int argc, const char **argv, const size_t *argvlen);
int redisFormatSdsCommandArgv(sds *target, int argc, const char ** argv, const size_t *argvlen);
void redisFreeCommand(char *cmd);
void redisFreeSdsCommand(sds cmd);
enum redisConnectionType {
REDIS_CONN_TCP,
REDIS_CONN_UNIX,
};
/* Context for a connection to Redis */
typedef struct redisContext {
int err; /* Error flags, 0 when there is no error */
char errstr[128]; /* String representation of error when applicable */
int fd;
int flags;
char *obuf; /* Write buffer */
redisReader *reader; /* Protocol reader */
enum redisConnectionType connection_type;
struct timeval *timeout;
struct {
char *host;
char *source_addr;
int port;
} tcp;
struct {
char *path;
} unix;
} redisContext;
redisContext *redisConnect(const char *ip, int port);
redisContext *redisConnectWithTimeout(const char *ip, int port, const struct timeval tv);
redisContext *redisConnectNonBlock(const char *ip, int port);
redisContext *redisConnectBindNonBlock(const char *ip, int port,
const char *source_addr);
redisContext *redisConnectBindNonBlockWithReuse(const char *ip, int port,
const char *source_addr);
redisContext *redisConnectUnix(const char *path);
redisContext *redisConnectUnixWithTimeout(const char *path, const struct timeval tv);
redisContext *redisConnectUnixNonBlock(const char *path);
redisContext *redisConnectFd(int fd);
int redisReconnect(redisContext *c);
int redisSetTimeout(redisContext *c, const struct timeval tv);
int redisEnableKeepAlive(redisContext *c);
void redisFree(redisContext *c);
int redisFreeKeepFd(redisContext *c);
int redisBufferRead(redisContext *c);
int redisBufferWrite(redisContext *c, int *done);
/* In a blocking context, this function first checks if there are unconsumed
* replies to return and returns one if so. Otherwise, it flushes the output
* buffer to the socket and reads until it has a reply. In a non-blocking
* context, it will return unconsumed replies until there are no more. */
int redisGetReply(redisContext *c, void **reply);
int redisGetReplyFromReader(redisContext *c, void **reply);
/* Write a formatted command to the output buffer. Use these functions in blocking mode
* to get a pipeline of commands. */
int redisAppendFormattedCommand(redisContext *c, const char *cmd, size_t len);
/* Write a command to the output buffer. Use these functions in blocking mode
* to get a pipeline of commands. */
int redisvAppendCommand(redisContext *c, const char *format, va_list ap);
int redisAppendCommand(redisContext *c, const char *format, ...);
int redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
/* Issue a command to Redis. In a blocking context, it is identical to calling
* redisAppendCommand, followed by redisGetReply. The function will return
* NULL if there was an error in performing the request, otherwise it will
* return the reply. In a non-blocking context, it is identical to calling
* only redisAppendCommand and will always return NULL. */
void *redisvCommand(redisContext *c, const char *format, va_list ap);
void *redisCommand(redisContext *c, const char *format, ...);
void *redisCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
#ifdef __cplusplus
}
#endif
#endif