stream.[ch], ass_mp: new stream function for whole-file reads

Add new stream_read_complete() function which reads the complete
contents of file. Use that in ass_mp.c which had custom code to do the
same.

3 files changed, 56 insertions, 34 deletions

diff --git a/stream/stream.c b/stream/stream.c
index 6f35252e3d..86dd61389e 100644
--- a/stream/stream.c
+++ b/stream/stream.c
@@ -29,6 +29,8 @@
 #include <fcntl.h>
 #include <strings.h>
 
+#include "talloc.h"
+
 #include "config.h"
 
 #if HAVE_WINSOCK2_H
@@ -658,3 +660,35 @@ unsigned char* stream_read_line(stream_t *s,unsigned char* mem, int max, int utf
   if(s->eof && ptr == mem) return NULL;
   return mem;
 }
+
+struct bstr stream_read_complete(struct stream *s, void *talloc_ctx,
+                                 int max_size, int padding_bytes)
+{
+    if (max_size > 1000000000)
+        abort();
+
+    int bufsize;
+    int total_read = 0;
+    int padding = FFMAX(padding_bytes, 1);
+    char *buf = NULL;
+    if (s->end_pos > max_size)
+        return (struct bstr){NULL, 0};
+    if (s->end_pos > 0)
+        bufsize = s->end_pos + padding;
+    else
+        bufsize = 1000;
+    while (1) {
+        buf = talloc_realloc_size(talloc_ctx, buf, bufsize);
+        int readsize = stream_read(s, buf + total_read, bufsize - total_read);
+        total_read += readsize;
+        if (total_read < bufsize)
+            break;
+        if (bufsize > max_size) {
+            talloc_free(buf);
+            return (struct bstr){NULL, 0};
+        }
+        bufsize = FFMIN(bufsize + (bufsize >> 1), max_size + padding);
+    }
+    buf = talloc_realloc_size(talloc_ctx, buf, total_read + padding);
+    return (struct bstr){buf, total_read};
+}
diff --git a/stream/stream.h b/stream/stream.h
index 413e80ad91..94bfb0e343 100644
--- a/stream/stream.h
+++ b/stream/stream.h
@@ -28,6 +28,8 @@
 #include <sys/types.h>
 #include <fcntl.h>
 
+#include "bstr.h"
+
 #ifndef O_BINARY
 #define O_BINARY 0
 #endif
@@ -331,6 +333,14 @@ inline static int stream_skip(stream_t *s,off_t len){
 }
 
 struct MPOpts;
+/*
+ * Return allocated buffer for all data until EOF.
+ * If amount of data would be more than max_size return NULL as data ptr.
+ * Make the allocated buffer padding_bytes larger than the data read.
+ * Write number of bytes read at *amount_read.
+ */
+struct bstr stream_read_complete(struct stream *s, void *talloc_ctx,
+                                 int max_size, int padding_bytes);
 void stream_reset(stream_t *s);
 int stream_control(stream_t *s, int cmd, void *arg);
 stream_t* new_stream(int fd,int type);
diff --git a/sub/ass_mp.c b/sub/ass_mp.c
index 98602ace03..78f607bc7a 100644
--- a/sub/ass_mp.c
+++ b/sub/ass_mp.c
@@ -233,50 +233,28 @@ ASS_Track *mp_ass_read_subdata(ASS_Library *library, sub_data *subdata,
 ASS_Track *mp_ass_read_stream(ASS_Library *library, const char *fname,
                               char *charset)
 {
-    int i;
-    char *buf = NULL;
     ASS_Track *track;
-    size_t sz = 0;
-    size_t buf_alloc = 0;
-    stream_t *fd;
 
-    fd = open_stream(fname, NULL, NULL);
-    if (!fd)
+    struct stream *s = open_stream(fname, NULL, NULL);
+    if (!s)
         // Stream code should have printed an error already
         return NULL;
-    if (fd->end_pos > STREAM_BUFFER_SIZE)
-        /* read entire file if size is known */
-        buf_alloc = fd->end_pos;
-    else
-        buf_alloc = 1000;
-    for (;;) {
-        if (sz > 100000000) {
-            mp_tmsg(MSGT_ASS, MSGL_ERR, "Refusing to load subtitle file "
-                    "larger than 100 MB: %s\n", fname);
-            sz = 0;
-            break;
-        }
-        buf_alloc = FFMAX(buf_alloc, sz + (sz >> 1));
-        buf_alloc = FFMIN(buf_alloc, 100000001);
-        buf = realloc(buf, buf_alloc + 1);
-        i = stream_read(fd, buf + sz, buf_alloc - sz);
-        if (i <= 0)
-            break;
-        sz += i;
-    }
-    free_stream(fd);
-    if (!sz) {
-        free(buf);
+    struct bstr content = stream_read_complete(s, NULL, 100000000, 1);
+    if (content.start == NULL)
+        mp_tmsg(MSGT_ASS, MSGL_ERR, "Refusing to load subtitle file "
+                "larger than 100 MB: %s\n", fname);
+    free_stream(s);
+    if (content.len == 0) {
+        talloc_free(content.start);
         return NULL;
     }
-    buf[sz] = 0;
-    buf = realloc(buf, sz + 1);
-    track = ass_read_memory(library, buf, sz, charset);
+    content.start[content.len] = 0;
+    track = ass_read_memory(library, content.start, content.len, charset);
     if (track) {
         free(track->name);
         track->name = strdup(fname);
     }
-    free(buf);
+    talloc_free(content.start);
     return track;
 }