/* SDSLib 2.0 -- A C dynamic strings library
 *
 * Copyright (c) 2006-2015, Salvatore Sanfilippo <antirez at gmail dot com>
 * Copyright (c) 2015, Oran Agra
 * Copyright (c) 2015, Redis Labs, Inc
 * 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 __SDS_H
#define __SDS_H
#ifdef __cplusplus
extern "C" {
#endif

#define SDS_MAX_PREALLOC (1024 * 1024)
#ifdef _MSC_VER
#define __attribute__(x)
typedef long long ssize_t;
#define SSIZE_MAX (LLONG_MAX >> 1)
#endif

#include <sys/types.h>
#include <stdarg.h>
#include <stdint.h>

typedef char *sds;

/* Note: sdshdr5 is never used, we just access the flags byte directly.
 * However is here to document the layout of type 5 SDS strings. */
struct __attribute__((__packed__)) sdshdr5 {
    unsigned char flags; /* 3 lsb of type, and 5 msb of string length */
    char          buf[];
};

struct __attribute__((__packed__)) sdshdr8 {
    uint8_t       len;   /* used */
    uint8_t       alloc; /* excluding the header and null terminator */
    unsigned char flags; /* 3 lsb of type, 5 unused bits */
    char          buf[];
};

struct __attribute__((__packed__)) sdshdr16 {
    uint16_t      len;   /* used */
    uint16_t      alloc; /* excluding the header and null terminator */
    unsigned char flags; /* 3 lsb of type, 5 unused bits */
    char          buf[];
};

struct __attribute__((__packed__)) sdshdr32 {
    uint32_t      len;   /* used */
    uint32_t      alloc; /* excluding the header and null terminator */
    unsigned char flags; /* 3 lsb of type, 5 unused bits */
    char          buf[];
};

struct __attribute__((__packed__)) sdshdr64 {
    uint64_t      len;   /* used */
    uint64_t      alloc; /* excluding the header and null terminator */
    unsigned char flags; /* 3 lsb of type, 5 unused bits */
    char          buf[];
};

#define SDS_TYPE_5        0
#define SDS_TYPE_8        1
#define SDS_TYPE_16       2
#define SDS_TYPE_32       3
#define SDS_TYPE_64       4
#define SDS_TYPE_MASK     7
#define SDS_TYPE_BITS     3
#define SDS_HDR_VAR(T, s) struct sdshdr##T *sh = (struct sdshdr##T *)((s) - (sizeof(struct sdshdr##T)));
#define SDS_HDR(T, s)     ((struct sdshdr##T *)((s) - (sizeof(struct sdshdr##T))))
#define SDS_TYPE_5_LEN(f) ((f) >> SDS_TYPE_BITS)

static inline size_t sdslen(const sds s) {
    unsigned char flags = s[-1];
    switch (flags & SDS_TYPE_MASK) {
        case SDS_TYPE_5:
            return SDS_TYPE_5_LEN(flags);
        case SDS_TYPE_8:
            return SDS_HDR(8, s)->len;
        case SDS_TYPE_16:
            return SDS_HDR(16, s)->len;
        case SDS_TYPE_32:
            return SDS_HDR(32, s)->len;
        case SDS_TYPE_64:
            return SDS_HDR(64, s)->len;
    }
    return 0;
}

static inline size_t sdsavail(const sds s) {
    unsigned char flags = s[-1];
    switch (flags & SDS_TYPE_MASK) {
        case SDS_TYPE_5: {
            return 0;
        }
        case SDS_TYPE_8: {
            SDS_HDR_VAR(8, s);
            return sh->alloc - sh->len;
        }
        case SDS_TYPE_16: {
            SDS_HDR_VAR(16, s);
            return sh->alloc - sh->len;
        }
        case SDS_TYPE_32: {
            SDS_HDR_VAR(32, s);
            return sh->alloc - sh->len;
        }
        case SDS_TYPE_64: {
            SDS_HDR_VAR(64, s);
            return sh->alloc - sh->len;
        }
    }
    return 0;
}

static inline void sdssetlen(sds s, size_t newlen) {
    unsigned char flags = s[-1];
    switch (flags & SDS_TYPE_MASK) {
        case SDS_TYPE_5: {
            unsigned char *fp = ((unsigned char *)s) - 1;
            *fp               = (unsigned char)(SDS_TYPE_5 | (newlen << SDS_TYPE_BITS));
        } break;
        case SDS_TYPE_8:
            SDS_HDR(8, s)->len = (uint8_t)newlen;
            break;
        case SDS_TYPE_16:
            SDS_HDR(16, s)->len = (uint16_t)newlen;
            break;
        case SDS_TYPE_32:
            SDS_HDR(32, s)->len = (uint32_t)newlen;
            break;
        case SDS_TYPE_64:
            SDS_HDR(64, s)->len = (uint64_t)newlen;
            break;
    }
}

static inline void sdsinclen(sds s, size_t inc) {
    unsigned char flags = s[-1];
    switch (flags & SDS_TYPE_MASK) {
        case SDS_TYPE_5: {
            unsigned char *fp     = ((unsigned char *)s) - 1;
            unsigned char  newlen = SDS_TYPE_5_LEN(flags) + (unsigned char)inc;
            *fp                   = SDS_TYPE_5 | (newlen << SDS_TYPE_BITS);
        } break;
        case SDS_TYPE_8:
            SDS_HDR(8, s)->len += (uint8_t)inc;
            break;
        case SDS_TYPE_16:
            SDS_HDR(16, s)->len += (uint16_t)inc;
            break;
        case SDS_TYPE_32:
            SDS_HDR(32, s)->len += (uint32_t)inc;
            break;
        case SDS_TYPE_64:
            SDS_HDR(64, s)->len += (uint64_t)inc;
            break;
    }
}

/* sdsalloc() = sdsavail() + sdslen() */
static inline size_t sdsalloc(const sds s) {
    unsigned char flags = s[-1];
    switch (flags & SDS_TYPE_MASK) {
        case SDS_TYPE_5:
            return SDS_TYPE_5_LEN(flags);
        case SDS_TYPE_8:
            return SDS_HDR(8, s)->alloc;
        case SDS_TYPE_16:
            return SDS_HDR(16, s)->alloc;
        case SDS_TYPE_32:
            return SDS_HDR(32, s)->alloc;
        case SDS_TYPE_64:
            return SDS_HDR(64, s)->alloc;
    }
    return 0;
}

static inline void sdssetalloc(sds s, size_t newlen) {
    unsigned char flags = s[-1];
    switch (flags & SDS_TYPE_MASK) {
        case SDS_TYPE_5:
            /* Nothing to do, this type has no total allocation info. */
            break;
        case SDS_TYPE_8:
            SDS_HDR(8, s)->alloc = (uint8_t)newlen;
            break;
        case SDS_TYPE_16:
            SDS_HDR(16, s)->alloc = (uint16_t)newlen;
            break;
        case SDS_TYPE_32:
            SDS_HDR(32, s)->alloc = (uint32_t)newlen;
            break;
        case SDS_TYPE_64:
            SDS_HDR(64, s)->alloc = (uint64_t)newlen;
            break;
    }
}

sds  sdsnewlen(const void *init, size_t initlen);
sds  sdsnew(const char *init);
sds  sdsempty(void);
sds  sdsdup(const sds s);
void sdsfree(sds s);
sds  sdsgrowzero(sds s, size_t len);
sds  sdscatlen(sds s, const void *t, size_t len);
sds  sdscat(sds s, const char *t);
sds  sdscatsds(sds s, const sds t);
sds  sdscpylen(sds s, const char *t, size_t len);
sds  sdscpy(sds s, const char *t);

sds sdscatvprintf(sds s, const char *fmt, va_list ap);
#ifdef __GNUC__
sds sdscatprintf(sds s, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
#else
sds sdscatprintf(sds s, const char *fmt, ...);
#endif

sds  sdscatfmt(sds s, char const *fmt, ...);
sds  sdstrim(sds s, const char *cset);
int  sdsrange(sds s, ssize_t start, ssize_t end);
void sdsupdatelen(sds s);
void sdsclear(sds s);
int  sdscmp(const sds s1, const sds s2);
sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count);
void sdsfreesplitres(sds *tokens, int count);
void sdstolower(sds s);
void sdstoupper(sds s);
sds  sdsfromlonglong(long long value);
sds  sdscatrepr(sds s, const char *p, size_t len);
sds *sdssplitargs(const char *line, int *argc);
sds  sdsmapchars(sds s, const char *from, const char *to, size_t setlen);
sds  sdsjoin(char **argv, int argc, char *sep);
sds  sdsjoinsds(sds *argv, int argc, const char *sep, size_t seplen);

/* Low level functions exposed to the user API */
sds    sdsMakeRoomFor(sds s, size_t addlen);
void   sdsIncrLen(sds s, int incr);
sds    sdsRemoveFreeSpace(sds s);
size_t sdsAllocSize(sds s);
void  *sdsAllocPtr(sds s);

/* Export the allocator used by SDS to the program using SDS.
 * Sometimes the program SDS is linked to, may use a different set of
 * allocators, but may want to allocate or free things that SDS will
 * respectively free or allocate. */
void *sds_malloc(size_t size);
void *sds_realloc(void *ptr, size_t size);
void  sds_free(void *ptr);

#ifdef REDIS_TEST
int sdsTest(int argc, char *argv[]);
#endif

#ifdef __cplusplus
}
#endif
#endif