hiredis.h

/*
 * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
 * Copyright (c) 2010-2014, Pieter Noordhuis <pcnoordhuis at gmail dot com>
 * Copyright (c) 2015, Matt Stancliff <matt at genges dot com>,
 *                     Jan-Erik Rediger <janerik at fnordig 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 13
#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_sock;
} 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);

/**
 * Reconnect the given context using the saved information.
 *
 * This re-uses the exact same connect options as in the initial connection.
 * host, ip (or path), timeout and bind address are reused,
 * flags are used unmodified from the existing context.
 *
 * Returns REDIS_OK on successfull connect or REDIS_ERR otherwise.
 */
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