From: short <>
Date: Mon, 1 Sep 2003 16:31:00 +0000 (+0000)
Subject: Implemented seek() and tell() for r/o streams of 'http'.
X-Git-Tag: gnome_vfs_httpcaptive_2_3_8captive1~12
X-Git-Url: http://git.jankratochvil.net/?p=gnome-vfs-httpcaptive.git;a=commitdiff_plain;h=b681983bd9666febbe1cecda5357b8b003cd7257

Implemented seek() and tell() for r/o streams of 'http'.
---

diff --git a/modules/http-method.c b/modules/http-method.c
index 317513d..cba1274 100644
--- a/modules/http-method.c
+++ b/modules/http-method.c
@@ -100,6 +100,9 @@ http_debug_printf (char *fmt, ...)
 /* Standard HTTP proxy port */
 #define DEFAULT_HTTP_PROXY_PORT 8080
 
+/* Maximum amount of data to read if seek()ed forward. Otherwise make a new connection. */
+#define MAX_BUFFER_SEEK_SKIP_READ	0x10000
+
 /* GConf paths and keys */
 #define PATH_GCONF_GNOME_VFS "/system/http_proxy"
 #define ITEM_GCONF_HTTP_PROXY_PORT "port"
@@ -211,8 +214,11 @@ typedef struct {
 	/* File info for this file */
 	GnomeVFSFileInfo *file_info;
 
-	/* Bytes read so far.  */
-	GnomeVFSFileSize bytes_read;
+	/* File offset of current pointer of 'socket_buffer'. */
+	GnomeVFSFileOffset socket_buffer_offset;
+
+	/* Offset; Current file position. */
+	GnomeVFSFileOffset offset;
 
 	/* Bytes to be written... */
 	GByteArray *to_be_written;
@@ -1825,7 +1831,7 @@ do_close (GnomeVFSMethod *method,
 	} else {
 		result = GNOME_VFS_OK;
 	}
-	
+
 	http_handle_close (old_handle, context);
 	g_free (old_handle);
 	
@@ -1840,7 +1846,7 @@ do_write (GnomeVFSMethod *method,
 	  GnomeVFSMethodHandle *method_handle,
 	  gconstpointer buffer,
 	  GnomeVFSFileSize num_bytes,
-	  GnomeVFSFileSize *bytes_read,
+	  GnomeVFSFileSize *bytes_written,
 	  GnomeVFSContext *context)
 {
 	HttpFileHandle *handle;
@@ -1849,11 +1855,14 @@ do_write (GnomeVFSMethod *method,
 
 	handle = (HttpFileHandle *) method_handle;
 
+	if (handle->offset != 0)
+		return GNOME_VFS_ERROR_NOT_SUPPORTED;
+
 	if(handle->to_be_written == NULL) {
 		handle->to_be_written = g_byte_array_new();
 	}
 	handle->to_be_written = g_byte_array_append(handle->to_be_written, buffer, num_bytes);
-	*bytes_read = num_bytes;
+	*bytes_written = num_bytes;
 	
 	DEBUG_HTTP (("-Write (0)"));
 	
@@ -1880,10 +1889,50 @@ do_read (GnomeVFSMethod *method,
 	if (handle->file_info->flags & GNOME_VFS_FILE_INFO_FIELDS_SIZE) {
 		GnomeVFSFileSize max_bytes;
 
-		max_bytes = handle->file_info->size - handle->bytes_read;
+		max_bytes = MAX (0, handle->file_info->size - handle->offset);
 		num_bytes = MIN (max_bytes, num_bytes);
 	}
 
+	if (!num_bytes) {
+		*bytes_read = 0;
+		return GNOME_VFS_OK;
+	}
+
+	if (1
+	    && handle->offset >  handle->socket_buffer_offset
+	    && handle->offset <= handle->socket_buffer_offset+MAX_BUFFER_SEEK_SKIP_READ) {
+static char drop_buffer[0x1000];
+GnomeVFSFileSize bytes, bytes_read;
+GnomeVFSResult result;
+
+		while ((bytes=MIN(sizeof(drop_buffer), handle->offset - handle->socket_buffer_offset))) {
+			result = gnome_vfs_socket_buffer_read (handle->socket_buffer, drop_buffer, 
+					bytes, &bytes_read);
+			if (result != GNOME_VFS_OK)
+				return result;
+			handle->socket_buffer_offset += bytes_read;
+		}
+	}
+
+	if (handle->offset != handle->socket_buffer_offset) {
+		GnomeVFSURI *uri = handle->uri;
+		gchar *extra_headers;
+
+		gnome_vfs_uri_ref(uri);
+		http_handle_close (handle, context);
+		extra_headers = g_strdup_printf("Range: bytes=%" G_GINT64_FORMAT "-\r\n",(gint64)handle->offset);
+		result = make_request (handle, uri, "GET", NULL, extra_headers,
+				       context);
+		g_free (extra_headers);
+		gnome_vfs_uri_unref(uri);
+		if (result != GNOME_VFS_OK) {
+			/* FIXME: 'method_handle' is now broken! */
+			memset(handle, 0, sizeof (*handle));
+			return result;
+		}
+		handle->socket_buffer_offset = handle->offset;
+	}
+
 	result = gnome_vfs_socket_buffer_read (handle->socket_buffer, buffer, 
 			num_bytes, bytes_read);
 	
@@ -1891,7 +1940,8 @@ do_read (GnomeVFSMethod *method,
 		return GNOME_VFS_ERROR_EOF;
 	}				       
 
-	handle->bytes_read += *bytes_read;
+	handle->socket_buffer_offset += *bytes_read;
+	handle->offset += *bytes_read;
 
 	DEBUG_HTTP (("-Read (%d)", result));
 	ANALYZE_HTTP ("==> -do_read");
@@ -1899,6 +1949,53 @@ do_read (GnomeVFSMethod *method,
 	return result;
 }
 
+static GnomeVFSResult
+do_seek (GnomeVFSMethod *method,
+	 GnomeVFSMethodHandle *method_handle,
+	 GnomeVFSSeekPosition  whence,
+	 GnomeVFSFileOffset    offset,
+	 GnomeVFSContext *context)
+{
+	HttpFileHandle *handle;
+
+	handle = (HttpFileHandle *) method_handle;
+
+	if (handle->to_be_written != NULL)
+		return GNOME_VFS_ERROR_NOT_SUPPORTED;
+
+	switch (whence) {
+	case GNOME_VFS_SEEK_START:
+		handle->offset = offset;
+		break;
+	case GNOME_VFS_SEEK_CURRENT:
+		handle->offset += offset;
+		break;
+	case GNOME_VFS_SEEK_END:
+		if (!(handle->file_info->flags & GNOME_VFS_FILE_INFO_FIELDS_SIZE))
+			return GNOME_VFS_ERROR_NOT_SUPPORTED;
+		handle->offset = handle->file_info->size + offset;
+		break;
+	default:
+		g_return_val_if_reached(GNOME_VFS_ERROR_NOT_SUPPORTED);
+	}
+
+	return GNOME_VFS_OK;
+}
+
+static GnomeVFSResult
+do_tell (GnomeVFSMethod *method,
+	 GnomeVFSMethodHandle *method_handle,
+	 GnomeVFSFileOffset *offset_return)
+{
+	HttpFileHandle *handle;
+
+	handle = (HttpFileHandle *) method_handle;
+
+	*offset_return = handle->offset;
+
+	return GNOME_VFS_OK;
+}
+
 /* Directory handling - WebDAV servers only */
 
 static void
@@ -2788,8 +2885,8 @@ static GnomeVFSMethod method = {
 	do_close,
 	do_read,
 	do_write,
-	NULL, /* seek */
-	NULL, /* tell */
+	do_seek,
+	do_tell,
 	NULL, /* truncate_handle */
 	do_open_directory,
 	do_close_directory,