BLI_dynstr.c

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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 2
 * 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, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 * Dynamically sized string ADT
 */

#include <stdarg.h>
#include <string.h>

#include "MEM_guardedalloc.h"
#include "BLI_blenlib.h"
#include "BLI_dynstr.h"

#ifdef _WIN32
#ifndef vsnprintf
#define vsnprintf _vsnprintf
#endif
#endif

#ifndef va_copy
# ifdef __va_copy
#  define va_copy(a,b) __va_copy(a,b)
# else /* !__va_copy */
#  define va_copy(a,b) ((a)=(b))
# endif /* __va_copy */
#endif /* va_copy */

/***/

typedef struct DynStrElem DynStrElem;
struct DynStrElem {
    DynStrElem *next;
    
    char *str;
};

struct DynStr {
    DynStrElem *elems, *last;
    int curlen;
};

/***/

DynStr *BLI_dynstr_new(void)
{
    DynStr *ds= MEM_mallocN(sizeof(*ds), "DynStr");
    ds->elems= ds->last= NULL;
    ds->curlen= 0;
    
    return ds;
}

void BLI_dynstr_append(DynStr *ds, const char *cstr)
{
    DynStrElem *dse= malloc(sizeof(*dse));
    int cstrlen= strlen(cstr);
    
    dse->str= malloc(cstrlen+1);
    memcpy(dse->str, cstr, cstrlen+1);
    dse->next= NULL;
    
    if (!ds->last)
        ds->last= ds->elems= dse;
    else
        ds->last= ds->last->next= dse;

    ds->curlen+= cstrlen;
}

void BLI_dynstr_nappend(DynStr *ds, const char *cstr, int len)
{
    DynStrElem *dse= malloc(sizeof(*dse));
    int cstrlen= BLI_strnlen(cstr, len);

    dse->str= malloc(cstrlen+1);
    memcpy(dse->str, cstr, cstrlen);
    dse->str[cstrlen] = '\0';
    dse->next= NULL;

    if (!ds->last)
        ds->last= ds->elems= dse;
    else
        ds->last= ds->last->next= dse;

    ds->curlen+= cstrlen;
}

void BLI_dynstr_vappendf(DynStr *ds, const char *format, va_list args)
{
    char *message, fixedmessage[256];
    int len= sizeof(fixedmessage);
    const int maxlen= 65536;
    int retval;

    while(1) {
        va_list args_cpy;
        if(len == sizeof(fixedmessage))
            message= fixedmessage;
        else
            message= MEM_callocN(sizeof(char) * len, "BLI_dynstr_appendf");

        /* cant reuse the same args, so work on a copy */
        va_copy(args_cpy, args);
        retval= vsnprintf(message, len, format, args_cpy);
        va_end(args_cpy);

        if(retval == -1) {
            /* -1 means not enough space, but on windows it may also mean
             * there is a formatting error, so we impose a maximum length */
            if(message != fixedmessage)
                MEM_freeN(message);
            message= NULL;

            len *= 2;
            if(len > maxlen) {
                fprintf(stderr, "BLI_dynstr_append text too long or format error.\n");
                break;
            }
        }
        else if(retval >= len) {
            /* in C99 the actual length required is returned */
            if(message != fixedmessage)
                MEM_freeN(message);
            message= NULL;

            /* retval doesnt include \0 terminator */
            len= retval + 1;
        }
        else
            break;
    }

    if(message) {
        BLI_dynstr_append(ds, message);

        if(message != fixedmessage)
            MEM_freeN(message);
    }
}

void BLI_dynstr_appendf(DynStr *ds, const char *format, ...)
{
    va_list args;
    char *message, fixedmessage[256];
    int len= sizeof(fixedmessage);
    const int maxlen= 65536;
    int retval;

    /* note that it's tempting to just call BLI_dynstr_vappendf here
     * and avoid code duplication, that crashes on some system because
     * va_start/va_end have to be called for each vsnprintf call */

    while(1) {
        if(len == sizeof(fixedmessage))
            message= fixedmessage;
        else
            message= MEM_callocN(sizeof(char)*(len), "BLI_dynstr_appendf");

        va_start(args, format);
        retval= vsnprintf(message, len, format, args);
        va_end(args);

        if(retval == -1) {
            /* -1 means not enough space, but on windows it may also mean
             * there is a formatting error, so we impose a maximum length */
            if(message != fixedmessage)
                MEM_freeN(message);
            message= NULL;

            len *= 2;
            if(len > maxlen) {
                fprintf(stderr, "BLI_dynstr_append text too long or format error.\n");
                break;
            }
        }
        else if(retval >= len) {
            /* in C99 the actual length required is returned */
            if(message != fixedmessage)
                MEM_freeN(message);
            message= NULL;

            /* retval doesnt include \0 terminator */
            len= retval + 1;
        }
        else
            break;
    }

    if(message) {
        BLI_dynstr_append(ds, message);

        if(message != fixedmessage)
            MEM_freeN(message);
    }
}

int BLI_dynstr_get_len(DynStr *ds)
{
    return ds->curlen;
}

void BLI_dynstr_get_cstring_ex(DynStr *ds, char *rets)
{
    char *s;
    DynStrElem *dse;

    for (s= rets, dse= ds->elems; dse; dse= dse->next) {
        int slen= strlen(dse->str);

        memcpy(s, dse->str, slen);

        s+= slen;
    }
    rets[ds->curlen]= '\0';
}

char *BLI_dynstr_get_cstring(DynStr *ds)
{
    char *rets= MEM_mallocN(ds->curlen+1, "dynstr_cstring");
    BLI_dynstr_get_cstring_ex(ds, rets);
    return rets;
}

void BLI_dynstr_free(DynStr *ds)
{
    DynStrElem *dse;
    
    for (dse= ds->elems; dse; ) {
        DynStrElem *n= dse->next;
        
        free(dse->str);
        free(dse);
        
        dse= n;
    }
    
    MEM_freeN(ds);
}