Add GZIP header processing to GZlibCompressor/GZlibDecompressor

Add GZlibCompressor:file-info property. If it contains a non-NULL
GFileInfo, and the compressor is in GZIP mode, the filename and
modification time from the file info are written to the GZIP header
in the output data.

Add GZlibDeompressor:file-info property. If the decompressor is in GZIP
mode, and the GZIP data contains a GZIP header, the filename and
modification time are read from it, stored in a GFileInfo, and the
file-info property is notified.

Bug #617691.

docs/reference/gio/gio-sections.txt

@@ -2054,6 +2054,8 @@ g_converter_output_stream_get_type
 GZlibCompressor
 GZlibCompressorFormat
 g_zlib_compressor_new
+g_zlib_compressor_get_file_info
+g_zlib_compressor_set_file_info
 <SUBSECTION Standard>
 GZlibCompressorClass
 G_TYPE_ZLIB_COMPRESSOR
@@ -2071,6 +2073,7 @@ g_zlib_compressor_get_type
 <TITLE>GZlibDecompressor</TITLE>
 GZlibDecompressor
 g_zlib_decompressor_new
+g_zlib_decompressor_get_file_info
 <SUBSECTION Standard>
 GZlibDecompressorClass
 G_TYPE_ZLIB_DECOMPRESSOR

gio/gio.symbols

@@ -1423,6 +1423,8 @@ g_unix_fd_list_steal_fds
 #if IN_FILE(__G_ZLIB_COMPRESSOR_C__)
 g_zlib_compressor_get_type G_GNUC_CONST
 g_zlib_compressor_new
+g_zlib_compressor_get_file_info
+g_zlib_compressor_set_file_info
 #endif
 #endif
 
@@ -1430,6 +1432,7 @@ g_zlib_compressor_new
 #if IN_FILE(__G_ZLIB_DECOMPRESSOR_C__)
 g_zlib_decompressor_get_type G_GNUC_CONST
 g_zlib_decompressor_new
+g_zlib_decompressor_get_file_info
 #endif
 #endif
 

gio/gzlibcompressor.c

@@ -28,6 +28,7 @@
 #include <zlib.h>
 #include <string.h>
 
+#include "gfileinfo.h"
 #include "gioerror.h"
 #include "gioenums.h"
 #include "gioenumtypes.h"
@@ -37,7 +38,8 @@
 enum {
   PROP_0,
   PROP_FORMAT,
-  PROP_LEVEL
+  PROP_LEVEL,
+  PROP_FILE_INFO
 };
 
 /**
@@ -63,8 +65,34 @@ struct _GZlibCompressor
   GZlibCompressorFormat format;
   int level;
   z_stream zstream;
+  gz_header gzheader;
+  GFileInfo *file_info;
 };
 
+static void
+g_zlib_compressor_set_gzheader (GZlibCompressor *compressor)
+{
+  const gchar *filename;
+
+  if (compressor->format != G_ZLIB_COMPRESSOR_FORMAT_GZIP ||
+      compressor->file_info == NULL)
+    return;
+
+  memset (&compressor->gzheader, 0, sizeof (gz_header));
+  compressor->gzheader.os = 0x03; /* Unix */
+
+  filename = g_file_info_get_name (compressor->file_info);
+  compressor->gzheader.name = (Bytef *) filename;
+  compressor->gzheader.name_max = filename ? strlen (filename) + 1 : 0;
+
+  compressor->gzheader.time =
+      (uLong) g_file_info_get_attribute_uint64 (compressor->file_info,
+                                                G_FILE_ATTRIBUTE_TIME_MODIFIED);
+
+  if (deflateSetHeader (&compressor->zstream, &compressor->gzheader) != Z_OK)
+    g_warning ("unexpected zlib error: %s\n", compressor->zstream.msg);
+}
+
 G_DEFINE_TYPE_WITH_CODE (GZlibCompressor, g_zlib_compressor, G_TYPE_OBJECT,
 			 G_IMPLEMENT_INTERFACE (G_TYPE_CONVERTER,
 						g_zlib_compressor_iface_init))
@@ -78,6 +106,9 @@ g_zlib_compressor_finalize (GObject *object)
 
   deflateEnd (&compressor->zstream);
 
+  if (compressor->file_info)
+    g_object_unref (compressor->file_info);
+
   G_OBJECT_CLASS (g_zlib_compressor_parent_class)->finalize (object);
 }
 
@@ -102,6 +133,10 @@ g_zlib_compressor_set_property (GObject      *object,
       compressor->level = g_value_get_int (value);
       break;
 
+    case PROP_FILE_INFO:
+      g_zlib_compressor_set_file_info (compressor, g_value_get_object (value));
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -129,6 +164,10 @@ g_zlib_compressor_get_property (GObject    *object,
       g_value_set_int (value, compressor->level);
       break;
 
+    case PROP_FILE_INFO:
+      g_value_set_object (value, compressor->file_info);
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -172,6 +211,8 @@ g_zlib_compressor_constructed (GObject *object)
 
   if (res != Z_OK)
     g_warning ("unexpected zlib error: %s\n", compressor->zstream.msg);
+
+  g_zlib_compressor_set_gzheader (compressor);
 }
 
 static void
@@ -203,6 +244,24 @@ g_zlib_compressor_class_init (GZlibCompressorClass *klass)
 						     G_PARAM_READWRITE |
 						     G_PARAM_CONSTRUCT_ONLY |
 						     G_PARAM_STATIC_STRINGS));
+
+  /**
+   * GZlibCompressor:file-info:
+   *
+   * If set to a non-%NULL #GFileInfo object, and #GZlibCompressor:format is
+   * %G_ZLIB_COMPRESSOR_FORMAT_GZIP, the compressor will write the file name
+   * and modification time from the file info to the the GZIP header.
+   *
+   * Since: 2.26
+   */
+  g_object_class_install_property (gobject_class,
+                                   PROP_FILE_INFO,
+                                   g_param_spec_object ("file-info",
+                                                       P_("file info"),
+                                                       P_("File info"),
+                                                       G_TYPE_FILE_INFO,
+                                                       G_PARAM_READWRITE |
+                                                       G_PARAM_STATIC_STRINGS));
 }
 
 /**
@@ -230,6 +289,59 @@ g_zlib_compressor_new (GZlibCompressorFormat format,
   return compressor;
 }
 
+/**
+ * g_zlib_compressor_get_file_info:
+ * @compressor: a #GZlibCompressor
+ *
+ * Returns the #GZlibCompressor:file-info property.
+ *
+ * Returns: (transfer none): a #GFileInfo, or %NULL
+ *
+ * Since: 2.26
+ */
+GFileInfo *
+g_zlib_compressor_get_file_info (GZlibCompressor *compressor)
+{
+  g_return_val_if_fail (G_IS_ZLIB_COMPRESSOR (compressor), NULL);
+
+  return compressor->file_info;
+}
+
+/**
+ * g_zlib_compressor_set_file_info:
+ * @compressor: a #GZlibCompressor
+ * @file_info: (allow-none): a #GFileInfo
+ *
+ * Sets @file_info in @compressor. If non-%NULL, and @compressor's
+ * #GZlibCompressor:format property is %G_ZLIB_COMPRESSOR_FORMAT_GZIP,
+ * it will be used to set the file name and modification time in
+ * the GZIP header of the compressed data.
+ *
+ * Note: it is an error to call this function while a compression is in
+ * progress; it may only be called immediately after creation of @compressor,
+ * or after resetting it with g_converter_reset().
+ *
+ * Since: 2.26
+ */
+void
+g_zlib_compressor_set_file_info (GZlibCompressor *compressor,
+                                 GFileInfo       *file_info)
+{
+  g_return_if_fail (G_IS_ZLIB_COMPRESSOR (compressor));
+
+  if (file_info == compressor->file_info)
+    return;
+
+  if (compressor->file_info)
+    g_object_unref (compressor->file_info);
+  if (file_info)
+    g_object_ref (file_info);
+  compressor->file_info = file_info;
+  g_object_notify (G_OBJECT (compressor), "file-info");
+
+  g_zlib_compressor_set_gzheader (compressor);
+}
+
 static void
 g_zlib_compressor_reset (GConverter *converter)
 {
@@ -239,6 +351,9 @@ g_zlib_compressor_reset (GConverter *converter)
   res = deflateReset (&compressor->zstream);
   if (res != Z_OK)
     g_warning ("unexpected zlib error: %s\n", compressor->zstream.msg);
+
+  /* deflateReset reset the header too, so re-set it */
+  g_zlib_compressor_set_gzheader (compressor);
 }
 
 static GConverterResult

gio/gzlibcompressor.h

@@ -28,6 +28,7 @@
 #define __G_ZLIB_COMPRESSOR_H__
 
 #include <gio/gconverter.h>
+#include <gio/gfileinfo.h>
 
 G_BEGIN_DECLS
 
@@ -50,6 +51,10 @@ GType            g_zlib_compressor_get_type (void) G_GNUC_CONST;
 GZlibCompressor *g_zlib_compressor_new (GZlibCompressorFormat format,
 					int level);
 
+GFileInfo       *g_zlib_compressor_get_file_info (GZlibCompressor *compressor);
+void             g_zlib_compressor_set_file_info (GZlibCompressor *compressor,
+                                                  GFileInfo       *file_info);
+
 G_END_DECLS
 
 #endif /* __G_ZLIB_COMPRESSOR_H__ */

gio/gzlibdecompressor.c

@@ -28,6 +28,7 @@
 #include <zlib.h>
 #include <string.h>
 
+#include "gfileinfo.h"
 #include "gioerror.h"
 #include "gioenums.h"
 #include "gioenumtypes.h"
@@ -36,7 +37,8 @@
 
 enum {
   PROP_0,
-  PROP_FORMAT
+  PROP_FORMAT,
+  PROP_FILE_INFO
 };
 
 /**
@@ -50,6 +52,12 @@ enum {
 
 static void g_zlib_decompressor_iface_init          (GConverterIface *iface);
 
+typedef struct {
+  gz_header gzheader;
+  char filename[257];
+  GFileInfo *file_info;
+} HeaderData;
+
 /**
  * GZlibDecompressor:
  *
@@ -61,8 +69,35 @@ struct _GZlibDecompressor
 
   GZlibCompressorFormat format;
   z_stream zstream;
+  HeaderData *header_data;
 };
 
+static void
+g_zlib_decompressor_set_gzheader (GZlibDecompressor *decompressor)
+{
+  if (decompressor->format != G_ZLIB_COMPRESSOR_FORMAT_GZIP)
+    return;
+
+  if (decompressor->header_data != NULL)
+    {
+      if (decompressor->header_data->file_info)
+        g_object_unref (decompressor->header_data->file_info);
+
+      memset (decompressor->header_data, 0, sizeof (HeaderData));
+    }
+  else
+    {
+      decompressor->header_data = g_new0 (HeaderData, 1);
+    }
+
+  decompressor->header_data->gzheader.name = (Bytef*) &decompressor->header_data->filename;
+  /* We keep one byte to guarantee the string is 0-terminated */
+  decompressor->header_data->gzheader.name_max = 256;
+
+  if (inflateGetHeader (&decompressor->zstream, &decompressor->header_data->gzheader) != Z_OK)
+    g_warning ("unexpected zlib error: %s\n", decompressor->zstream.msg);
+}
+
 G_DEFINE_TYPE_WITH_CODE (GZlibDecompressor, g_zlib_decompressor, G_TYPE_OBJECT,
 			 G_IMPLEMENT_INTERFACE (G_TYPE_CONVERTER,
 						g_zlib_decompressor_iface_init))
@@ -76,6 +111,13 @@ g_zlib_decompressor_finalize (GObject *object)
 
   inflateEnd (&decompressor->zstream);
 
+  if (decompressor->header_data != NULL)
+    {
+      if (decompressor->header_data->file_info)
+        g_object_unref (decompressor->header_data->file_info);
+      g_free (decompressor->header_data);
+    }
+
   G_OBJECT_CLASS (g_zlib_decompressor_parent_class)->finalize (object);
 }
 
@@ -119,6 +161,13 @@ g_zlib_decompressor_get_property (GObject    *object,
       g_value_set_enum (value, decompressor->format);
       break;
 
+    case PROP_FILE_INFO:
+      if (decompressor->header_data)
+        g_value_set_object (value, decompressor->header_data->file_info);
+      else
+        g_value_set_object (value, NULL);
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -156,6 +205,8 @@ g_zlib_decompressor_constructed (GObject *object)
 
   if (res != Z_OK)
     g_warning ("unexpected zlib error: %s\n", decompressor->zstream.msg);
+
+  g_zlib_decompressor_set_gzheader (decompressor);
 }
 
 static void
@@ -177,6 +228,25 @@ g_zlib_decompressor_class_init (GZlibDecompressorClass *klass)
 						      G_ZLIB_COMPRESSOR_FORMAT_ZLIB,
 						      G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
 						      G_PARAM_STATIC_STRINGS));
+
+  /**
+   * GZlibDecompressor:file-info:
+   *
+   * A #GFileInfo containing the information found in the GZIP header
+   * of the data stream processed, or %NULL if the header was not yet
+   * fully processed, is not present at all, or the compressor's
+   * #GZlibDecompressor:format property is not %G_ZLIB_COMPRESSOR_FORMAT_GZIP.
+   *
+   * Since: 2.26
+   */
+  g_object_class_install_property (gobject_class,
+                                   PROP_FILE_INFO,
+                                   g_param_spec_object ("file-info",
+                                                       P_("file info"),
+                                                       P_("File info"),
+                                                       G_TYPE_FILE_INFO,
+                                                       G_PARAM_READABLE |
+                                                       G_PARAM_STATIC_STRINGS));
 }
 
 /**
@@ -201,6 +271,31 @@ g_zlib_decompressor_new (GZlibCompressorFormat format)
   return decompressor;
 }
 
+/**
+ * g_zlib_decompressor_get_file_info:
+ * @decompressor: a #GZlibDecompressor
+ *
+ * Retrieves the #GFileInfo constructed from the GZIP header data
+ * of compressed data processed by @compressor, or %NULL if @decompressor's
+ * #GZlibDecompressor:format property is not %G_ZLIB_COMPRESSOR_FORMAT_GZIP,
+ * or the header data was not fully processed yet, or it not present in the
+ * data stream at all.
+ *
+ * Returns: (transfer none): a #GFileInfo, or %NULL
+ *
+ * Since: 2.26
+ */
+GFileInfo *
+g_zlib_decompressor_get_file_info (GZlibDecompressor *decompressor)
+{
+  g_return_val_if_fail (G_IS_ZLIB_DECOMPRESSOR (decompressor), NULL);
+
+  if (decompressor->header_data)
+    return decompressor->header_data->file_info;
+
+  return NULL;
+}
+
 static void
 g_zlib_decompressor_reset (GConverter *converter)
 {
@@ -210,6 +305,8 @@ g_zlib_decompressor_reset (GConverter *converter)
   res = inflateReset (&decompressor->zstream);
   if (res != Z_OK)
     g_warning ("unexpected zlib error: %s\n", decompressor->zstream.msg);
+
+  g_zlib_decompressor_set_gzheader (decompressor);
 }
 
 static GConverterResult
@@ -271,19 +368,40 @@ g_zlib_decompressor_convert (GConverter *converter,
 	return G_CONVERTER_ERROR;
       }
 
-  if (res == Z_OK || res == Z_STREAM_END)
+  g_assert (res == Z_OK || res == Z_STREAM_END);
-    {
+
   *bytes_read = inbuf_size - decompressor->zstream.avail_in;
   *bytes_written = outbuf_size - decompressor->zstream.avail_out;
 
+  if (decompressor->header_data != NULL &&
+      decompressor->header_data->gzheader.done == 1)
+    {
+      HeaderData *data = decompressor->header_data;
+
+      /* So we don't notify again */
+      data->gzheader.done = 2;
+
+      data->file_info = g_file_info_new ();
+      g_file_info_set_attribute_uint64 (data->file_info,
+                                        G_FILE_ATTRIBUTE_TIME_MODIFIED,
+                                        data->gzheader.time);
+      g_file_info_set_attribute_uint32 (data->file_info,
+                                        G_FILE_ATTRIBUTE_TIME_MODIFIED_USEC,
+                                        0);
+
+      if (data->filename[0] != '\0')
+        g_file_info_set_attribute_byte_string (data->file_info,
+                                               G_FILE_ATTRIBUTE_STANDARD_NAME,
+                                               data->filename);
+
+      g_object_notify (G_OBJECT (decompressor), "file-info");
+    }
+
   if (res == Z_STREAM_END)
     return G_CONVERTER_FINISHED;
   return G_CONVERTER_CONVERTED;
 }
 
-  g_assert_not_reached ();
-}
-
 static void
 g_zlib_decompressor_iface_init (GConverterIface *iface)
 {

gio/gzlibdecompressor.h

@@ -28,6 +28,7 @@
 #define __G_ZLIB_DECOMPRESSOR_H__
 
 #include <gio/gconverter.h>
+#include <gio/gfileinfo.h>
 
 G_BEGIN_DECLS
 
@@ -49,6 +50,8 @@ GType              g_zlib_decompressor_get_type (void) G_GNUC_CONST;
 
 GZlibDecompressor *g_zlib_decompressor_new (GZlibCompressorFormat format);
 
+GFileInfo         *g_zlib_decompressor_get_file_info (GZlibDecompressor *decompressor);
+
 G_END_DECLS
 
 #endif /* __G_ZLIB_DECOMPRESSOR_H__ */

gio/tests/filter-cat.c

@@ -49,6 +49,23 @@ static GOptionEntry entries[] = {
   {NULL}
 };
 
+static void
+decompressor_file_info_notify_cb (GZlibDecompressor *decompressor,
+                                  GParamSpec *pspec,
+                                  gpointer data)
+{
+  GFileInfo *file_info;
+  const gchar *filename;
+
+  file_info = g_zlib_decompressor_get_file_info (decompressor);
+  if (file_info == NULL)
+    return;
+
+  filename = g_file_info_get_name (file_info);
+  if (filename)
+    g_printerr ("Decompressor filename: %s\n", filename);
+}
+
 static void
 cat (GFile * file)
 {
@@ -79,6 +96,7 @@ cat (GFile * file)
       conv = (GConverter *)g_zlib_decompressor_new (gzip?G_ZLIB_COMPRESSOR_FORMAT_GZIP:G_ZLIB_COMPRESSOR_FORMAT_ZLIB);
       old = in;
       in = (GInputStream *) g_converter_input_stream_new (in, conv);
+      g_signal_connect (conv, "notify::file-info", G_CALLBACK (decompressor_file_info_notify_cb), NULL);
       g_object_unref (conv);
       g_object_unref (old);
     }
@@ -108,11 +126,29 @@ cat (GFile * file)
   if (compress)
     {
       GInputStream *old;
+      GFileInfo *in_file_info;
+
+      in_file_info = g_file_query_info (file,
+                                        G_FILE_ATTRIBUTE_STANDARD_NAME ","
+                                        G_FILE_ATTRIBUTE_TIME_MODIFIED,
+                                        G_FILE_QUERY_INFO_NONE,
+                                        NULL,
+                                        &error);
+      if (in_file_info == NULL)
+        {
+          g_printerr ("%s: %s: error reading file info: %s\n",
+                      g_get_prgname (), g_file_get_uri (file), error->message);
+          g_error_free (error);
+          return;
+        }
+
       conv = (GConverter *)g_zlib_compressor_new(gzip?G_ZLIB_COMPRESSOR_FORMAT_GZIP:G_ZLIB_COMPRESSOR_FORMAT_ZLIB, -1);
+      g_zlib_compressor_set_file_info (G_ZLIB_COMPRESSOR (conv), in_file_info);
       old = in;
       in = (GInputStream *) g_converter_input_stream_new (in, conv);
       g_object_unref (conv);
       g_object_unref (old);
+      g_object_unref (in_file_info);
     }
 
   while (1)