source: trunk/server/source3/lib/cbuf.c

/*
 * Samba Unix/Linux SMB client library
 *
 * Copyright (C) Gregor Beck 2010
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @file   cbuf.c
 * @author Gregor Beck <gb@sernet.de>
 * @date   Aug 2010
 *
 * @brief  A talloced character buffer.
 *
 */


#include "includes.h"
#include "cbuf.h"


struct cbuf {
        char*  buf;
        size_t pos;
        size_t size;
};


cbuf* cbuf_clear(cbuf* b)
{
        cbuf_setpos(b, 0);
        return b;
}

cbuf* cbuf_new(const void* ctx)
{
        cbuf* s = talloc(ctx, cbuf);
        if (s == NULL)
                return NULL;
        s->size = 32;
        s->buf  = (char *)talloc_size(s, s->size);
        if (s->size && (s->buf == NULL)) {
                talloc_free(s);
                return NULL;
        }
        return cbuf_clear(s);
}

cbuf* cbuf_copy(const cbuf* b)
{
        cbuf* s = talloc(talloc_parent(b), cbuf);
        if (s == NULL) {
                return NULL;
        }

        s->buf = (char *)talloc_memdup(s, b->buf, b->size); /* only up to pos? */

        /* XXX shallow did not work, because realloc */
        /* fails with multiple references */
        /* s->buf = talloc_reference(s, b->buf); */

        if (s->buf == NULL) {
                cbuf_delete(s);
                return NULL;
        }
        s->size = b->size;
        s->pos  = b->pos;
        return s;
}

void cbuf_delete(cbuf* b)
{
        talloc_free(b);
}

#define SWAP(A,B,T) do {                        \
                T tmp = A; A = B; B = tmp;      \
        } while(0)


void cbuf_swap(cbuf* b1, cbuf* b2)
{
        if (b1 == b2) {
                return;
        }
        talloc_reparent(b1, b2, b1->buf);
        talloc_reparent(b2, b1, b2->buf);
        SWAP(b1->buf,  b2->buf, char*);
        SWAP(b1->pos,  b2->pos, size_t);
        SWAP(b1->size, b2->size, size_t);
}



cbuf* cbuf_takeover(cbuf* b1, cbuf* b2)
{
        talloc_reparent(b2, b1, b2->buf);
        b1->buf = b2->buf;
        b1->pos = b2->pos;
        b1->size = b2->size;
        cbuf_delete(b2);
        return b1;
}

cbuf* cbuf_swapptr(cbuf* b, char** ptr, size_t len)
{
        void* p = talloc_parent(*ptr);
        SWAP(b->buf, *ptr, char*);
        talloc_steal(b, b->buf);
        talloc_steal(p, *ptr);
        b->size = talloc_get_size(b->buf);
        b->pos  = (len == -1) ? strlen(b->buf) : len;

        assert(b->pos <= b->size);
        return b;
}

cbuf* cbuf_resize(cbuf* b, size_t size)
{
        char* save_buf = b->buf;
        b->buf = talloc_realloc(b, b->buf, char, size);
        if (b->buf == NULL) {
                talloc_free(save_buf);
                b->size = 0;
        } else {
                b->size = size;
        }
        b->pos  = MIN(b->pos, b->size);
        return b->buf ? b : NULL;
}

char* cbuf_reserve(cbuf* b, size_t len)
{
        if(b->size < b->pos + len)
                cbuf_resize(b, MAX(2*b->size, b->pos + len));
        return b->buf ? b->buf + b->pos : NULL;
}

int cbuf_puts(cbuf* b, const char* str, size_t len)
{
        char* dst;

        if (b == NULL)
                return 0;

        if (len == -1) {
                len=strlen(str);
        }

        dst = cbuf_reserve(b, len+1);
        if (dst == NULL)
                return -1;

        memcpy(dst, str, len);
        dst[len] = '\0'; /* just to ease debugging */

        b->pos += len;
        assert(b->pos < b->size);

        return len;
}

int cbuf_putc(cbuf* b, char c) {
        char* dst;

        if (b == NULL)
                return 0;

        dst = cbuf_reserve(b, 2);
        if (dst == NULL) {
                return -1;
        }

        dst[0] = c;
        dst[1] = '\0'; /* just to ease debugging */

        b->pos++;
        assert(b->pos < b->size);

        return 1;
}

int cbuf_putdw(cbuf* b, uint32_t u) {
        char* dst;
        static const size_t LEN = sizeof(uint32_t);

        if (b == NULL)
                return 0;

        dst = cbuf_reserve(b, LEN);
        if (dst == NULL) {
                return -1;
        }

        SIVAL(dst, 0, u);

        b->pos += LEN;
        assert(b->pos <= b->size); /* no NULL termination*/

        return LEN;
}

size_t cbuf_getpos(const cbuf* b) {
        assert(b->pos <= b->size);
        return b->pos;
}

void cbuf_setpos(cbuf* b, size_t pos) {
        assert(pos <= b->size);
        b->pos = pos;
        if (pos < b->size)
                b->buf[pos] = '\0'; /* just to ease debugging */
}

char* cbuf_gets(cbuf* b, size_t idx) {
        assert(idx <= b->pos);

        if (cbuf_reserve(b, 1) == NULL)
                return NULL;

        b->buf[b->pos] = '\0';
        return b->buf + idx;
}

int cbuf_printf(cbuf* b, const char* fmt, ...)
{
        va_list args, args2;
        int len;
        char* dst = b->buf + b->pos;
        const int avail = b->size - b->pos;
        assert(avail >= 0);

        va_start(args, fmt);
        va_copy(args2, args);

        len = vsnprintf(dst, avail, fmt, args);

        if (len >= avail) {
                dst = cbuf_reserve(b, len+1);
                len = (dst != NULL) ? vsnprintf(dst, len+1, fmt, args2) : -1;
        }

        if (len > 0) {
                b->pos += len;
        }

        va_end(args);
        va_end(args2);
        assert(b->pos <= b->size);

        return len;
}

int cbuf_print_quoted_string(cbuf* ost, const char* s)
{
        int n = 1;
        cbuf_putc(ost,'"');

        while(true) {
                switch (*s) {
                case '\0':
                        cbuf_putc(ost, '"');
                        return n+1;

                case '"':
                case '\\':
                        cbuf_putc(ost, '\\');
                        n++;
                        /* no break */
                default:
                        cbuf_putc(ost, *s);
                        n++;
                }
                s++;
        }
}


int cbuf_print_quoted(cbuf* ost, const char* s, size_t len)
{
        int n = 1;
        int ret;
        cbuf_reserve(ost, len+2);

        cbuf_putc(ost,'"');

        while(len--) {
                switch (*s) {
                case '"':
                case '\\':
                        ret = cbuf_printf(ost, "\\%c", *s);
                        break;
                default:
                        if (isprint(*s) && ((*s == ' ') || !isspace(*s))) {
                                ret = cbuf_putc(ost, *s);
                        } else {
                                ret = cbuf_printf(ost, "\\%02x", *s);
                        }
                }
                s++;
                if (ret == -1) {
                        return -1;
                }
                n += ret;
        }
        ret = cbuf_putc(ost,'"');

        return (ret == -1) ? -1 : (n + ret);
}