stringbuf.c

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/*
    stringbuf: mimicking a bit of C++ to more safely handle strings

    copyright 2006-8 by the mpg123 project - free software under the terms of the LGPL 2.1
    see COPYING and AUTHORS files in distribution or http://mpg123.org
    initially written by Thomas Orgis
*/

#include "mpg123lib_intern.h"
#include "config.h"
#include "mpg123.h"
#include "compat.h"
#include <string.h>
#include "debug.h"

void attribute_align_arg mpg123_init_string(mpg123_string* sb)
{
    sb->p = NULL;
    sb->size = 0;
    sb->fill = 0;
}

void attribute_align_arg mpg123_free_string(mpg123_string* sb)
{
    if(sb->p != NULL) free(sb->p);
    mpg123_init_string(sb);
}

int attribute_align_arg mpg123_grow_string(mpg123_string* sb, size_t new)
{
    if(sb->size < new) return mpg123_resize_string(sb, new);
    else return 1;
}

int attribute_align_arg mpg123_resize_string(mpg123_string* sb, size_t new)
{
    debug3("resizing string pointer %p from %lu to %lu", (void*) sb->p, (unsigned long)sb->size, (unsigned long)new);
    if(new == 0)
    {
        if(sb->size && sb->p != NULL) free(sb->p);
        mpg123_init_string(sb);
        return 1;
    }
    if(sb->size != new)
    {
        char* t;
        debug("really!");
        t = (char*) safe_realloc(sb->p, new*sizeof(char));
        debug1("safe_realloc returned %p", (void*) t); 
        if(t != NULL)
        {
            sb->p = t;
            sb->size = new;
            return 1;
        }
        else return 0;
    }
    else return 1; /* success */
}

int attribute_align_arg mpg123_copy_string(mpg123_string* from, mpg123_string* to)
{
    size_t fill;
    char  *text;
    if(to == NULL) return -1;

    debug2("called copy_string with %p -> %p", (void*)from, (void*)to);
    if(from == NULL)
    {
        fill = 0;
        text = NULL;
    }
    else
    {
        fill = from->fill;
        text = from->p;
    }

    if(mpg123_resize_string(to, fill))
    {
        memcpy(to->p, text, fill);
        to->fill = fill;
        return 1;
    }
    else return 0;
}

int attribute_align_arg mpg123_add_string(mpg123_string* sb, const char* stuff)
{
    debug1("adding %s", stuff);
    return mpg123_add_substring(sb, stuff, 0, strlen(stuff));
}

int attribute_align_arg mpg123_add_substring(mpg123_string *sb, const char *stuff, size_t from, size_t count)
{
    debug("adding a substring");
    if(sb->fill) /* includes zero byte... */
    {
        if( (SIZE_MAX - sb->fill >= count) /* Avoid overflow. */
            && (sb->size >= sb->fill+count || mpg123_grow_string(sb, sb->fill+count)) )
        {
            memcpy(sb->p+sb->fill-1, stuff+from, count);
            sb->fill += count;
            sb->p[sb->fill-1] = 0; /* Terminate! */
        }
        else return 0;
    }
    else
    {
        if( count < SIZE_MAX && mpg123_grow_string(sb, count+1) )
        {
            memcpy(sb->p, stuff+from, count);
            sb->fill = count+1;
            sb->p[sb->fill-1] = 0; /* Terminate! */
        }
        else return 0;
    }
    return 1;
}

int attribute_align_arg mpg123_set_substring(mpg123_string* sb, const char* stuff, size_t from, size_t count)
{
    sb->fill = 0;
    return mpg123_add_substring(sb, stuff, from, count);
}

int attribute_align_arg mpg123_set_string(mpg123_string* sb, const char* stuff)
{
    sb->fill = 0;
    return mpg123_add_string(sb, stuff);
}