Keep track, in Wiretap, of whether the file is compressed, and provide

an API to fetch that.

When doing "Save" on a compressed file, write it out compressed.

In the Statistics -> Summary dialog and in capinfos, report whether the
file is gzip-compressed.

svn path=/trunk/; revision=42818

capinfos.c

@@ -191,6 +191,7 @@ typedef enum {
 typedef struct _capture_info {
   const char    *filename;
   guint16       file_type;
+  gboolean      iscompressed;
   int           file_encap;
   gint64        filesize;
 
@@ -358,7 +359,9 @@ print_stats(const gchar *filename, capture_info *cf_info)
   stop_time_t = (time_t)cf_info->stop_time;
 
   if (filename)           printf     ("File name:           %s\n", filename);
-  if (cap_file_type)      printf     ("File type:           %s\n", file_type_string);
+  if (cap_file_type)      printf     ("File type:           %s%s\n",
+                                      file_type_string,
+                                      cf_info->iscompressed ? " (gzip compressed)" : "");
   if (cap_file_encap)     printf     ("File encapsulation:  %s\n", file_encap_string);
   if (cap_file_encap && (cf_info->file_encap == WTAP_ENCAP_PER_PACKET)) {
     int i;
@@ -749,6 +752,7 @@ process_cap_file(wtap *wth, const char *filename)
 
   /* File Type */
   cf_info.file_type = wtap_file_type(wth);
+  cf_info.iscompressed = wtap_iscompressed(wth);
 
   /* File Encapsulation */
   cf_info.file_encap = wtap_file_encap(wth);

cfile.h

@@ -73,6 +73,7 @@ typedef struct _capture_file {
   gboolean     unsaved_changes; /* Does the capture file have changes that have not been saved? */
   gint64       f_datalen;       /* Size of capture file data (uncompressed) */
   guint16      cd_t;            /* File type of capture file */
+  gboolean     iscompressed;    /* TRUE if the file is compressed */
   int          lnk_t;           /* Link-layer type with which to save capture */
   guint32      count;           /* Total number of frames */
   guint32      displayed_count; /* Number of displayed frames */

file.c

@@ -530,6 +530,9 @@ cf_read(capture_file *cf, gboolean reloading)
   else
     cf_callback_invoke(cf_cb_file_read_started, cf);
 
+  /* Record whether the file is compressed. */
+  cf->iscompressed = wtap_iscompressed(cf->wth);
+
   /* Find the size of the file. */
   size = wtap_file_size(cf->wth, NULL);
 
@@ -3818,7 +3821,8 @@ cf_save_packets(capture_file *cf, const char *fname, guint save_format,
 
   cf_callback_invoke(cf_cb_file_save_started, (gpointer)fname);
 
-  if (save_format == cf->cd_t && !cf->unsaved_changes) {
+  if (save_format == cf->cd_t && compressed == cf->iscompressed
+      && !cf->unsaved_changes) {
     /* We're saving in the format it's already in, and there are no
        changes we have in memory that aren't saved to the file, so
        we can just move or copy the raw data. */

summary.c

@@ -141,6 +141,7 @@ summary_fill_in(capture_file *cf, summary_tally *st)
   st->filename = cf->filename;
   st->file_length = cf->f_datalen;
   st->file_type = cf->cd_t;
+  st->iscompressed = cf->iscompressed;
   st->is_tempfile = cf->is_tempfile;
   st->encap_type = cf->lnk_t;
   st->has_snap = cf->has_snap;

summary.h

@@ -33,7 +33,7 @@ typedef struct iface_options_tag {
     char	*name;
     char	*descr;
     char	*cfilter;
-	char	*isb_comment;
+    char	*isb_comment;
     guint64	drops;				/**< number of packet drops */
     gboolean	drops_known;	/**< TRUE if number of packet drops is known */
     gboolean	has_snap;		/**< TRUE if maximum capture packet length is known */
@@ -64,6 +64,7 @@ typedef struct _summary_tally {
     const char	*filename;
     gint64		file_length;	/**< file length in bytes */
     int			file_type;		/**< wiretap file type */
+    int         iscompressed;           /**< TRUE if file is compressed */
     int			encap_type;		/**< wiretap encapsulation type */
     gboolean	has_snap;		/**< TRUE if maximum capture packet length is known */
     int			snap;			/**< Maximum captured packet length */

ui/gtk/capture_file_dlg.c

@@ -1190,10 +1190,7 @@ file_save_cmd(action_after_save_e action_after_save, gpointer action_after_save_
      a copy and free it later. */
   fname = g_strdup(cfile.filename);
 
-  /* XXX - if we're editing a compressed capture file, we should
-     remember that it's compressed, and write it out in compressed
-     form. */
-  cf_save_packets(&cfile, fname, cfile.cd_t, FALSE);
+  cf_save_packets(&cfile, fname, cfile.cd_t, cfile.iscompressed);
   g_free(fname);
 }
 

ui/gtk/summary_dlg.c

@@ -238,7 +238,9 @@ summary_open_cb(GtkWidget *w _U_, gpointer d _U_)
   add_string_to_table(table, &row, "Length:", string_buff);
 
   /* format */
-  g_snprintf(string_buff, SUM_STR_MAX, "%s", wtap_file_type_string(summary.file_type));
+  g_snprintf(string_buff, SUM_STR_MAX, "%s%s",
+             wtap_file_type_string(summary.file_type),
+             summary.iscompressed? " (gzip compressed)" : "");
   add_string_to_table(table, &row, "Format:", string_buff);
 
   /* encapsulation */

wiretap/file_wrappers.c

@@ -121,6 +121,7 @@ struct wtap_reader {
 	gint64 start;           /* where the gzip data started, for rewinding */
 	gint64 raw;             /* where the raw data started, for seeking */
 	int compression;        /* 0: ?, 1: uncompressed, 2: zlib */
+	gboolean is_compressed; /* FALSE if completely uncompressed, TRUE otherwise */
 	/* seek request */
 	gint64 skip;            /* amount to skip (already rewound if backwards) */
 	int seek;               /* true if seek request pending */
@@ -128,8 +129,8 @@ struct wtap_reader {
 	int err;                /* error code */
 	const char *err_info;   /* additional error information string for some errors */
 
-	unsigned int  avail_in;  /* number of bytes available at next_in */
-	unsigned char *next_in;  /* next input byte */
+	unsigned int  avail_in; /* number of bytes available at next_in */
+	unsigned char *next_in; /* next input byte */
 #ifdef HAVE_LIBZ
 	/* zlib inflate stream */
 	z_stream strm;          /* stream structure in-place (not a pointer) */
@@ -140,7 +141,7 @@ struct wtap_reader {
 	void *fast_seek_cur;
 };
 
-/* values for gz_state compression */
+/* values for wtap_reader compression */
 #define UNKNOWN		0	/* look for a gzip header */
 #define UNCOMPRESSED	1	/* copy input directly */
 #ifdef HAVE_LIBZ
@@ -651,6 +652,7 @@ gz_head(FILE_T state)
 			inflateReset(&(state->strm));
 			state->strm.adler = crc32(0L, Z_NULL, 0);
 			state->compression = ZLIB;
+			state->is_compressed = TRUE;
 #ifdef Z_BLOCK
 			if (state->fast_seek) {
 				struct zlib_cur_seek_point *cur = g_malloc(sizeof(struct zlib_cur_seek_point));
@@ -786,6 +788,9 @@ filed_open(int fd)
 	/* open the file with the appropriate mode (or just use fd) */
 	state->fd = fd;
 
+	/* we don't yet know whether it's compressed */
+	state->is_compressed = FALSE;
+
 	/* save the current position for rewinding (only if reading) */
 	state->start = ws_lseek64(state->fd, 0, SEEK_CUR);
 	if (state->start == -1) state->start = 0;
@@ -1085,6 +1090,12 @@ file_fstat(FILE_T stream, ws_statb64 *statb, int *err)
 	return 0;
 }
 
+gboolean
+file_iscompressed(FILE_T stream)
+{
+	return stream->is_compressed;
+}
+
 int 
 file_read(void *buf, unsigned int len, FILE_T file)
 {

wiretap/file_wrappers.h

@@ -35,6 +35,7 @@ extern gint64 file_skip(FILE_T file, gint64 delta, int *err);
 extern gint64 file_tell(FILE_T stream);
 extern gint64 file_tell_raw(FILE_T stream);
 extern int file_fstat(FILE_T stream, ws_statb64 *statb, int *err);
+extern gboolean file_iscompressed(FILE_T stream);
 extern int file_read(void *buf, unsigned int count, FILE_T file);
 extern int file_getc(FILE_T stream);
 extern char *file_gets(char *buf, int len, FILE_T stream);

wiretap/wtap.c

@@ -78,6 +78,12 @@ wtap_file_type(wtap *wth)
 	return wth->file_type;
 }
 
+gboolean
+wtap_iscompressed(wtap *wth)
+{
+	return file_iscompressed((wth->fh == NULL) ? wth->random_fh : wth->fh);
+}
+
 guint
 wtap_snapshot_length(wtap *wth)
 {

wiretap/wtap.def

@@ -61,6 +61,7 @@ wtap_fstat
 wtap_get_bytes_dumped
 wtap_get_num_encap_types
 wtap_get_num_file_types
+wtap_iscompressed
 wtap_open_offline
 wtap_pcap_encap_to_wtap_encap
 wtap_phdr

wiretap/wtap.h

@@ -1074,6 +1074,7 @@ guint8 *wtap_buf_ptr(wtap *wth);
  * from the file so far. */
 gint64 wtap_read_so_far(wtap *wth);
 gint64 wtap_file_size(wtap *wth, int *err);
+gboolean wtap_iscompressed(wtap *wth);
 guint wtap_snapshot_length(wtap *wth); /* per file */
 int wtap_file_type(wtap *wth);
 int wtap_file_encap(wtap *wth);