input_stream: return allocated input_stream objects

Major API redesign: don't let the caller allocate the input_stream
object.  Let each input plugin allocate its own (derived/extended)
input_stream pointer.  The "data" attribute can now be removed, and
all input plugins simply cast the input_stream pointer to their own
structure (with an "struct input_stream base" as the first attribute).

3 files changed, 44 insertions, 47 deletions

diff --git a/src/archive/bz2_archive_plugin.c b/src/archive/bz2_archive_plugin.c
index 07d17440..75b4b1ec 100644
--- a/src/archive/bz2_archive_plugin.c
+++ b/src/archive/bz2_archive_plugin.c
@@ -45,10 +45,12 @@ struct bz2_archive_file {
 
 	char *name;
 	bool reset;
-	struct input_stream istream;
+	struct input_stream *istream;
 };
 
 struct bz2_input_stream {
+	struct input_stream base;
+
 	struct bz2_archive_file *archive;
 
 	bool eof;
@@ -111,7 +113,8 @@ bz2_open(const char *pathname, GError **error_r)
 	refcount_init(&context->ref);
 
 	//open archive
-	if (!input_stream_open(&context->istream, pathname, error_r)) {
+	context->istream = input_stream_open(pathname, error_r);
+	if (context->istream == NULL) {
 		g_free(context);
 		return NULL;
 	}
@@ -158,44 +161,42 @@ bz2_close(struct archive_file *file)
 
 	g_free(context->name);
 
-	input_stream_close(&context->istream);
+	input_stream_close(context->istream);
 	g_free(context);
 }
 
 /* single archive handling */
 
-static bool
-bz2_open_stream(struct archive_file *file, struct input_stream *is,
+static struct input_stream *
+bz2_open_stream(struct archive_file *file,
 		G_GNUC_UNUSED const char *path, GError **error_r)
 {
 	struct bz2_archive_file *context = (struct bz2_archive_file *) file;
 	struct bz2_input_stream *bis = g_new(struct bz2_input_stream, 1);
 
+	input_stream_init(&bis->base, &bz2_inputplugin);
+
 	bis->archive = context;
 
-	//setup file ops
-	is->plugin = &bz2_inputplugin;
-	//insert back reference
-	is->data = bis;
-	is->ready = true;
-	is->seekable = false;
+	bis->base.ready = true;
+	bis->base.seekable = false;
 
 	if (!bz2_alloc(bis, error_r)) {
 		g_free(bis);
-		return false;
+		return NULL;
 	}
 
 	bis->eof = false;
 
 	refcount_inc(&context->ref);
 
-	return true;
+	return &bis->base;
 }
 
 static void
 bz2_is_close(struct input_stream *is)
 {
-	struct bz2_input_stream *bis = (struct bz2_input_stream *)is->data;
+	struct bz2_input_stream *bis = (struct bz2_input_stream *)is;
 
 	bz2_destroy(bis);
 
@@ -215,7 +216,7 @@ bz2_fillbuffer(struct bz2_input_stream *bis, GError **error_r)
 	if (bzstream->avail_in > 0)
 		return true;
 
-	count = input_stream_read(&bis->archive->istream,
+	count = input_stream_read(bis->archive->istream,
 				  bis->buffer, sizeof(bis->buffer),
 				  error_r);
 	if (count == 0)
@@ -230,7 +231,7 @@ static size_t
 bz2_is_read(struct input_stream *is, void *ptr, size_t length,
 	    GError **error_r)
 {
-	struct bz2_input_stream *bis = (struct bz2_input_stream *)is->data;
+	struct bz2_input_stream *bis = (struct bz2_input_stream *)is;
 	bz_stream *bzstream;
 	int bz_result;
 	size_t nbytes = 0;
@@ -269,7 +270,7 @@ bz2_is_read(struct input_stream *is, void *ptr, size_t length,
 static bool
 bz2_is_eof(struct input_stream *is)
 {
-	struct bz2_input_stream *bis = (struct bz2_input_stream *)is->data;
+	struct bz2_input_stream *bis = (struct bz2_input_stream *)is;
 
 	return bis->eof;
 }
diff --git a/src/archive/iso9660_archive_plugin.c b/src/archive/iso9660_archive_plugin.c
index f6c6ed5f..38003da9 100644
--- a/src/archive/iso9660_archive_plugin.c
+++ b/src/archive/iso9660_archive_plugin.c
@@ -163,14 +163,16 @@ iso9660_archive_close(struct archive_file *file)
 /* single archive handling */
 
 struct iso9660_input_stream {
+	struct input_stream base;
+
 	struct iso9660_archive_file *archive;
 
 	iso9660_stat_t *statbuf;
 	size_t max_blocks;
 };
 
-static bool
-iso9660_archive_open_stream(struct archive_file *file, struct input_stream *is,
+static struct input_stream *
+iso9660_archive_open_stream(struct archive_file *file,
 		const char *pathname, GError **error_r)
 {
 	struct iso9660_archive_file *context =
@@ -178,6 +180,7 @@ iso9660_archive_open_stream(struct archive_file *file, struct input_stream *is,
 	struct iso9660_input_stream *iis;
 
 	iis = g_new(struct iso9660_input_stream, 1);
+	input_stream_init(&iis->base, &iso9660_input_plugin);
 
 	iis->archive = context;
 	iis->statbuf = iso9660_ifs_stat_translate(context->iso, pathname);
@@ -185,31 +188,26 @@ iso9660_archive_open_stream(struct archive_file *file, struct input_stream *is,
 		g_free(iis);
 		g_set_error(error_r, iso9660_quark(), 0,
 			    "not found in the ISO file: %s", pathname);
-		return false;
+		return NULL;
 	}
 
-	//setup file ops
-	is->plugin = &iso9660_input_plugin;
-	//insert back reference
-	is->data = iis;
-	is->ready = true;
+	iis->base.ready = true;
 	//we are not seekable
-	is->seekable = false;
+	iis->base.seekable = false;
 
-	is->size = iis->statbuf->size;
+	iis->base.size = iis->statbuf->size;
 
 	iis->max_blocks = CEILING(iis->statbuf->size, ISO_BLOCKSIZE);
 
 	refcount_inc(&context->ref);
 
-	return true;
+	return &iis->base;
 }
 
 static void
 iso9660_input_close(struct input_stream *is)
 {
-	struct iso9660_input_stream *iis =
-		(struct iso9660_input_stream *)is->data;
+	struct iso9660_input_stream *iis = (struct iso9660_input_stream *)is;
 
 	g_free(iis->statbuf);
 
@@ -220,8 +218,7 @@ iso9660_input_close(struct input_stream *is)
 static size_t
 iso9660_input_read(struct input_stream *is, void *ptr, size_t size, GError **error_r)
 {
-	struct iso9660_input_stream *iis =
-		(struct iso9660_input_stream *)is->data;
+	struct iso9660_input_stream *iis = (struct iso9660_input_stream *)is;
 	int toread, readed = 0;
 	int no_blocks, cur_block;
 	size_t left_bytes = iis->statbuf->size - is->offset;
diff --git a/src/archive/zzip_archive_plugin.c b/src/archive/zzip_archive_plugin.c
index 3e0c063c..7e59a093 100644
--- a/src/archive/zzip_archive_plugin.c
+++ b/src/archive/zzip_archive_plugin.c
@@ -125,13 +125,15 @@ zzip_archive_close(struct archive_file *file)
 /* single archive handling */
 
 struct zzip_input_stream {
+	struct input_stream base;
+
 	struct zzip_archive *archive;
 
 	ZZIP_FILE *file;
 };
 
-static bool
-zzip_archive_open_stream(struct archive_file *file, struct input_stream *is,
+static struct input_stream *
+zzip_archive_open_stream(struct archive_file *file,
 			 const char *pathname, GError **error_r)
 {
 	struct zzip_archive *context = (struct zzip_archive *) file;
@@ -139,6 +141,7 @@ zzip_archive_open_stream(struct archive_file *file, struct input_stream *is,
 	ZZIP_STAT z_stat;
 
 	zis = g_new(struct zzip_input_stream, 1);
+	input_stream_init(&zis->base, &zzip_input_plugin);
 
 	zis->archive = context;
 	zis->file = zzip_file_open(context->dir, pathname, 0);
@@ -146,29 +149,25 @@ zzip_archive_open_stream(struct archive_file *file, struct input_stream *is,
 		g_free(zis);
 		g_set_error(error_r, zzip_quark(), 0,
 			    "not found in the ZIP file: %s", pathname);
-		return false;
+		return NULL;
 	}
 
-	//setup file ops
-	is->plugin = &zzip_input_plugin;
-	//insert back reference
-	is->data = zis;
-	is->ready = true;
+	zis->base.ready = true;
 	//we are seekable (but its not recommendent to do so)
-	is->seekable = true;
+	zis->base.seekable = true;
 
 	zzip_file_stat(zis->file, &z_stat);
-	is->size = z_stat.st_size;
+	zis->base.size = z_stat.st_size;
 
 	refcount_inc(&context->ref);
 
-	return true;
+	return &zis->base;
 }
 
 static void
 zzip_input_close(struct input_stream *is)
 {
-	struct zzip_input_stream *zis = (struct zzip_input_stream *)is->data;
+	struct zzip_input_stream *zis = (struct zzip_input_stream *)is;
 
 	zzip_file_close(zis->file);
 	zzip_archive_close(&zis->archive->base);
@@ -179,7 +178,7 @@ static size_t
 zzip_input_read(struct input_stream *is, void *ptr, size_t size,
 		GError **error_r)
 {
-	struct zzip_input_stream *zis = (struct zzip_input_stream *)is->data;
+	struct zzip_input_stream *zis = (struct zzip_input_stream *)is;
 	int ret;
 
 	ret = zzip_file_read(zis->file, ptr, size);
@@ -197,7 +196,7 @@ zzip_input_read(struct input_stream *is, void *ptr, size_t size,
 static bool
 zzip_input_eof(struct input_stream *is)
 {
-	struct zzip_input_stream *zis = (struct zzip_input_stream *)is->data;
+	struct zzip_input_stream *zis = (struct zzip_input_stream *)is;
 
 	return (goffset)zzip_tell(zis->file) == is->size;
 }
@@ -206,7 +205,7 @@ static bool
 zzip_input_seek(struct input_stream *is,
 		goffset offset, int whence, GError **error_r)
 {
-	struct zzip_input_stream *zis = (struct zzip_input_stream *)is->data;
+	struct zzip_input_stream *zis = (struct zzip_input_stream *)is;
 	zzip_off_t ofs = zzip_seek(zis->file, offset, whence);
 	if (ofs != -1) {
 		g_set_error(error_r, zzip_quark(), ofs,