/* * Unbuffered io for ffmpeg system * Copyright (c) 2001 Fabrice Bellard * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */#include "avformat.h"static int default_interrupt_cb(void);URLProtocol *first_protocol = NULL;URLInterruptCB *url_interrupt_cb = default_interrupt_cb;int register_protocol(URLProtocol *protocol){    URLProtocol **p;    p = &first_protocol;    while (*p != NULL) p = &(*p)->next;    *p = protocol;    protocol->next = NULL;    return 0;}int url_open(URLContext **puc, const char *filename, int flags){    URLContext *uc;    URLProtocol *up;    const char *p;    char proto_str[128], *q;    int err;    p = filename;    q = proto_str;    while (*p != '\0' && *p != ':') {        /* protocols can only contain alphabetic chars */        if (!isalpha(*p))            goto file_proto;        if ((q - proto_str) < sizeof(proto_str) - 1)            *q++ = *p;        p++;    }    /* if the protocol has length 1, we consider it is a dos drive */    if (*p == '\0' || (q - proto_str) <= 1) {    file_proto:        strcpy(proto_str, "file");    } else {        *q = '\0';    }        up = first_protocol;    while (up != NULL) {        if (!strcmp(proto_str, up->name))            goto found;        up = up->next;    }    err = -ENOENT;    goto fail; found:    uc = av_malloc(sizeof(URLContext) + strlen(filename));    if (!uc) {        err = -ENOMEM;        goto fail;    }    strcpy(uc->filename, filename);    uc->prot = up;    uc->flags = flags;    uc->is_streamed = 0; /* default = not streamed */    uc->max_packet_size = 0; /* default: stream file */    err = up->url_open(uc, filename, flags);    if (err < 0) {        av_free(uc);        *puc = NULL;        return err;    }    *puc = uc;    return 0; fail:    *puc = NULL;    return err;}int url_read(URLContext *h, unsigned char *buf, int size){    int ret;    if (h->flags & URL_WRONLY)        return -EIO;    ret = h->prot->url_read(h, buf, size);    return ret;}#ifdef CONFIG_ENCODERSint url_write(URLContext *h, unsigned char *buf, int size){    int ret;    if (!(h->flags & (URL_WRONLY | URL_RDWR)))        return -EIO;    /* avoid sending too big packets */    if (h->max_packet_size && size > h->max_packet_size)        return -EIO;     ret = h->prot->url_write(h, buf, size);    return ret;}#endif //CONFIG_ENCODERSoffset_t url_seek(URLContext *h, offset_t pos, int whence){    offset_t ret;    if (!h->prot->url_seek)        return -EPIPE;    ret = h->prot->url_seek(h, pos, whence);    return ret;}int url_close(URLContext *h){    int ret;    ret = h->prot->url_close(h);    av_free(h);    return ret;}int url_exist(const char *filename){    URLContext *h;    if (url_open(&h, filename, URL_RDONLY) < 0)        return 0;    url_close(h);    return 1;}offset_t url_filesize(URLContext *h){    offset_t pos, size;        pos = url_seek(h, 0, SEEK_CUR);    size = url_seek(h, -1, SEEK_END)+1;    url_seek(h, pos, SEEK_SET);    return size;}/*  * Return the maximum packet size associated to packetized file * handle. If the file is not packetized (stream like http or file on * disk), then 0 is returned. *  * @param h file handle * @return maximum packet size in bytes */int url_get_max_packet_size(URLContext *h){    return h->max_packet_size;}void url_get_filename(URLContext *h, char *buf, int buf_size){    pstrcpy(buf, buf_size, h->filename);}static int default_interrupt_cb(void){    return 0;}/**  * The callback is called in blocking functions to test regulary if * asynchronous interruption is needed. -EINTR is returned in this * case by the interrupted function. 'NULL' means no interrupt * callback is given.   */void url_set_interrupt_cb(URLInterruptCB *interrupt_cb){    if (!interrupt_cb)        interrupt_cb = default_interrupt_cb;    url_interrupt_cb = interrupt_cb;}