mod_url progress
[assman] / src / mod_url.c
index c8c62cb..5c0f81f 100644 (file)
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
+#include "assman_impl.h"
+#include "tpool.h"
+#include "md4.h"
 
 #ifdef BUILD_MOD_URL
+#include <pthread.h>
 #include <curl/curl.h>
 
+enum {
+       DL_UNKNOWN,
+       DL_STARTED,
+       DL_ERROR,
+       DL_DONE
+};
+
+struct file_info {
+       char *url;
+       char *cache_fname;
+
+       FILE *cache_file;
+
+       /* fopen-thread waits until the state becomes known (request starts transmitting or fails) */
+       int state;
+       pthread_cond_t state_cond;
+       pthread_mutex_t state_mutex;
+};
+
+static void *fop_open(const char *fname, void *udata);
+static void fop_close(void *fp, void *udata);
+static long fop_seek(void *fp, long offs, int whence, void *udata);
+static long fop_read(void *fp, void *buf, long size, void *udata);
+
+static void exit_cleanup(void);
+static void download(void *data);
+static size_t recv_callback(char *ptr, size_t size, size_t nmemb, void *udata);
 static const char *get_temp_dir(void);
 
 static char *tmpdir, *cachedir;
+static struct thread_pool *tpool;
+static CURL **curl;
 
 struct ass_fileops *ass_alloc_url(const char *url)
 {
        static int done_init;
        struct ass_fileops *fop;
+       int i;
 
        if(!done_init) {
                curl_global_init(CURL_GLOBAL_ALL);
-               atexit(curl_global_cleanup);
-               done_init = 1;
+               atexit(exit_cleanup);
 
                if(!*ass_mod_url_cachedir) {
                        strcpy(ass_mod_url_cachedir, "assman_cache");
                }
-               tmpdir = get_temp_dir();
+               tmpdir = (char*)get_temp_dir();
                if(!(cachedir = malloc(strlen(ass_mod_url_cachedir) + strlen(tmpdir) + 2))) {
                        fprintf(stderr, "assman: failed to allocate cachedir path buffer\n");
-                       return 0;
+                       goto init_failed;
                }
                sprintf(cachedir, "%s/%s", tmpdir, ass_mod_url_cachedir);
+
+               if(ass_mod_url_max_threads <= 0) {
+                       ass_mod_url_max_threads = 8;
+               }
+
+               if(!(curl = calloc(ass_mod_url_max_threads, sizeof *curl))) {
+                       perror("assman: failed to allocate curl context table");
+                       goto init_failed;
+               }
+               for(i=0; i<ass_mod_url_max_threads; i++) {
+                       if(!(curl[i] = curl_easy_init())) {
+                               goto init_failed;
+                       }
+                       curl_easy_setopt(curl[i], CURLOPT_WRITEFUNCTION, recv_callback);
+               }
+
+               if(!(tpool = ass_tpool_create(ass_mod_url_max_threads))) {
+                       fprintf(stderr, "assman: failed to create thread pool\n");
+                       goto init_failed;
+               }
+
+               done_init = 1;
        }
 
        if(!(fop = malloc(sizeof *fop))) {
                return 0;
        }
+       if(!(fop->udata = malloc(strlen(url) + 1))) {
+               free(fop);
+               return 0;
+       }
+       strcpy(fop->udata, url);
 
-       fop->udata = 0;
        fop->open = fop_open;
        fop->close = fop_close;
        fop->seek = fop_seek;
        fop->read = fop_read;
        return fop;
+
+init_failed:
+       free(cachedir);
+       if(curl) {
+               for(i=0; i<ass_mod_url_max_threads; i++) {
+                       if(curl[i]) {
+                               curl_easy_cleanup(curl[i]);
+                       }
+               }
+               free(curl);
+       }
+       return 0;
 }
 
+static void exit_cleanup(void)
+{
+       int i;
+
+       if(tpool) {
+               ass_tpool_destroy(tpool);
+       }
+       if(curl) {
+               for(i=0; i<ass_mod_url_max_threads; i++) {
+                       if(curl[i]) {
+                               curl_easy_cleanup(curl[i]);
+                       }
+               }
+               free(curl);
+       }
+       curl_global_cleanup();
+}
+
+
 void ass_free_url(struct ass_fileops *fop)
 {
 }
 
+static char *cache_filename(const char *fname, const char *url_prefix)
+{
+       MD4_CTX md4ctx;
+       unsigned char sum[16];
+       char sumstr[33];
+       char *resfname;
+       int i;
+       int fname_len = strlen(fname);
+       int prefix_len = strlen(url_prefix);
+       int url_len = fname_len + prefix_len + 1;
+
+       char *url = alloca(url_len + 1);
+       sprintf(url, "%s/%s", url_prefix, fname);
+
+       MD4Init(&md4ctx);
+       MD4Update(&md4ctx, (unsigned char*)url, url_len);
+       MD4Final((unsigned char*)sum, &md4ctx);
+
+       for(i=0; i<16; i++) {
+               sprintf(sumstr + i * 2, "%x", (unsigned int)sum[i]);
+       }
+       sumstr[32] = 0;
+
+       prefix_len = strlen(cachedir);
+       if(!(resfname = malloc(prefix_len + fname_len + 20))) {
+               return 0;
+       }
+       sprintf(resfname, "%s/%s-%s", cachedir, fname, sumstr);
+       return resfname;
+}
+
 static void *fop_open(const char *fname, void *udata)
 {
-       return 0;       /* TODO */
+       struct file_info *file;
+       int state;
+
+       if(!(file = malloc(sizeof *file))) {
+               ass_errno = ENOMEM;
+               return 0;
+       }
+       if(!(file->cache_fname = cache_filename(fname, udata))) {
+               free(file);
+               ass_errno = ENOMEM;
+               return 0;
+       }
+       if(!(file->cache_file = fopen(file->cache_fname, "wb"))) {
+               fprintf(stderr, "assman: mod_url: failed to open cache file (%s) for writing: %s\n",
+                               file->cache_fname, strerror(errno));
+               ass_errno = errno;
+               free(file->cache_fname);
+               free(file);
+               return 0;
+       }
+
+       file->state = DL_UNKNOWN;
+       pthread_mutex_init(&file->state_mutex, 0);
+       pthread_cond_init(&file->state_cond, 0);
+
+       ass_tpool_enqueue(tpool, file, download, 0);
+
+       /* wait until the file changes state */
+       pthread_mutex_lock(&file->state_mutex);
+       while(file->state == DL_UNKNOWN) {
+               pthread_cond_wait(&file->state_cond, &file->state_mutex);
+       }
+       state = file->state;
+       pthread_mutex_unlock(&file->state_mutex);
+
+       if(state == DL_ERROR) {
+               /* the worker stopped, so we can safely cleanup and return error */
+               fclose(file->cache_file);
+               remove(file->cache_fname);
+               free(file->cache_fname);
+               pthread_cond_destroy(&file->state_cond);
+               pthread_mutex_destroy(&file->state_mutex);
+               free(file);
+               ass_errno = ENOENT;     /* TODO: differentiate between 403 and 404 */
+               return 0;
+       }
+       return file;
+}
+
+static void wait_done(struct file_info *file)
+{
+       pthread_mutex_lock(&file->state_mutex);
+       while(file->state != DL_DONE && file->state != DL_ERROR) {
+               pthread_cond_wait(&file->state_cond, &file->state_mutex);
+       }
+       pthread_mutex_unlock(&file->state_mutex);
 }
 
 static void fop_close(void *fp, void *udata)
 {
+       struct file_info *file = fp;
+
+       wait_done(file);        /* TODO: stop download instead of waiting to finish */
+
+       fclose(file->cache_file);
+       if(file->state == DL_ERROR) remove(file->cache_fname);
+       free(file->cache_fname);
+       pthread_cond_destroy(&file->state_cond);
+       pthread_mutex_destroy(&file->state_mutex);
+       free(file);
 }
 
 static long fop_seek(void *fp, long offs, int whence, void *udata)
 {
-       return 0;
+       struct file_info *file = fp;
+       wait_done(file);
+
+       fseek(file->cache_file, offs, whence);
+       return ftell(file->cache_file);
 }
 
 static long fop_read(void *fp, void *buf, long size, void *udata)
 {
-       return 0;
+       struct file_info *file = fp;
+       wait_done(file);
+
+       return fread(buf, 1, size, file->cache_file);
 }
 
-#else
+/* this is the function called by the worker threads to perform the download
+ * signal state changes, and prepare the cache file for reading
+ */
+static void download(void *data)
+{
+       int tid, res;
+       struct file_info *file = data;
+
+       tid = ass_tpool_thread_id(tpool);
+
+       curl_easy_setopt(curl[tid], CURLOPT_URL, file->url);
+       curl_easy_setopt(curl[tid], CURLOPT_WRITEDATA, file);
+       res = curl_easy_perform(curl[tid]);
+
+       pthread_mutex_lock(&file->state_mutex);
+       if(res == CURLE_OK) {
+               file->state = DL_DONE;
+               fclose(file->cache_file);
+               if(!(file->cache_file = fopen(file->cache_fname, "rb"))) {
+                       fprintf(stderr, "assman: failed to reopen cache file (%s) for reading: %s\n",
+                                       file->cache_fname, strerror(errno));
+                       file->state = DL_ERROR;
+               }
+       } else {
+               file->state = DL_ERROR;
+       }
+       pthread_cond_broadcast(&file->state_cond);
+       pthread_mutex_unlock(&file->state_mutex);
+}
+
+/* this function is called by curl to pass along downloaded data chunks */
+static size_t recv_callback(char *ptr, size_t size, size_t count, void *udata)
+{
+       struct file_info *file = udata;
+
+       pthread_mutex_lock(&file->state_mutex);
+       if(file->state == DL_UNKNOWN) {
+               file->state = DL_STARTED;
+               pthread_cond_broadcast(&file->state_cond);
+       }
+       pthread_mutex_unlock(&file->state_mutex);
+
+       return fwrite(ptr, size, count, file->cache_file);
+}
+
+#ifdef WIN32
+#include <windows.h>
+
+static const char *get_temp_dir(void)
+{
+       static char buf[MAX_PATH + 1];
+       GetTempPathA(MAX_PATH + 1, buf);
+       return buf;
+}
+#else  /* UNIX */
+static const char *get_temp_dir(void)
+{
+       char *env = getenv("TMPDIR");
+       return env ? env : "/tmp";
+}
+#endif
+
+
+
+#else  /* don't build mod_url */
 struct ass_fileops *ass_alloc_url(const char *url)
 {
        fprintf(stderr, "assman: compiled without URL asset source support\n");