[PATCH] RFC: impliment gzipped output for notmuch dump

[David Bremner <david@tethera.net>]

---

This obviously needs at least one piece of tidying, and some tests.

My motivation here is the ability to make gzipped backups from within
notmuch, e.g. as part of an upgrade procedure.


 Makefile.local   |  2 +-
 configure        | 19 ++++++++++++++++++-
 notmuch-client.h |  4 +++-
 notmuch-dump.c   | 41 +++++++++++++++++++++++++++--------------
 4 files changed, 49 insertions(+), 17 deletions(-)

diff --git a/Makefile.local b/Makefile.local
index cb7b106..e5a20a7 100644
--- a/Makefile.local
+++ b/Makefile.local
@@ -41,7 +41,7 @@ PV_FILE=bindings/python/notmuch/version.py
 # Smash together user's values with our extra values
 FINAL_CFLAGS = -DNOTMUCH_VERSION=$(VERSION) $(CPPFLAGS) $(CFLAGS) $(WARN_CFLAGS) $(extra_cflags) $(CONFIGURE_CFLAGS)
 FINAL_CXXFLAGS = $(CPPFLAGS) $(CXXFLAGS) $(WARN_CXXFLAGS) $(extra_cflags) $(extra_cxxflags) $(CONFIGURE_CXXFLAGS)
-FINAL_NOTMUCH_LDFLAGS = $(LDFLAGS) -Lutil -lutil -Llib -lnotmuch $(AS_NEEDED_LDFLAGS) $(GMIME_LDFLAGS) $(TALLOC_LDFLAGS)
+FINAL_NOTMUCH_LDFLAGS = $(LDFLAGS) -Lutil -lutil -Llib -lnotmuch $(AS_NEEDED_LDFLAGS) $(GMIME_LDFLAGS) $(TALLOC_LDFLAGS) $(ZLIB_LDFLAGS)
 FINAL_NOTMUCH_LINKER = CC
 ifneq ($(LINKER_RESOLVES_LIBRARY_DEPENDENCIES),1)
 FINAL_NOTMUCH_LDFLAGS += $(CONFIGURE_LDFLAGS)
diff --git a/configure b/configure
index 1d430b9..02ef785 100755
--- a/configure
+++ b/configure
@@ -340,6 +340,18 @@ else
     errors=$((errors + 1))
 fi
 
+printf "Checking for zlib development files... "
+have_zlib=0
+if pkg-config --exists zlib; then
+    printf "Yes.\n"
+    have_zlib=1
+    zlib_cflags=$(pkg-config --cflags zlib)
+    zlib_ldflags=$(pkg-config --libs zlib)
+else
+    printf "No.\n"
+    errors=$((errors + 1))
+fi
+
 printf "Checking for talloc development files... "
 if pkg-config --exists talloc; then
     printf "Yes.\n"
@@ -844,6 +856,10 @@ XAPIAN_LDFLAGS = ${xapian_ldflags}
 GMIME_CFLAGS = ${gmime_cflags}
 GMIME_LDFLAGS = ${gmime_ldflags}
 
+# Flags needed to compile and link against zlib
+ZLIB_CFLAGS = ${zlib_cflags}
+ZLIB_LDFLAGS = ${zlib_ldflags}
+
 # Flags needed to compile and link against talloc
 TALLOC_CFLAGS = ${talloc_cflags}
 TALLOC_LDFLAGS = ${talloc_ldflags}
@@ -882,6 +898,7 @@ CONFIGURE_CFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS)      \\
 		   -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER)
 
 CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS)    \\
+		     \$(ZLIB_CFLAGS)					 \\
 		     \$(TALLOC_CFLAGS) -DHAVE_VALGRIND=\$(HAVE_VALGRIND) \\
 		     \$(VALGRIND_CFLAGS) \$(XAPIAN_CXXFLAGS)             \\
 		     -DHAVE_STRCASESTR=\$(HAVE_STRCASESTR)               \\
@@ -892,5 +909,5 @@ CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS)    \\
 		     -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT)       \\
 		     -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER)
 
-CONFIGURE_LDFLAGS =  \$(GMIME_LDFLAGS) \$(TALLOC_LDFLAGS) \$(XAPIAN_LDFLAGS)
+CONFIGURE_LDFLAGS =  \$(GMIME_LDFLAGS) \$(TALLOC_LDFLAGS) \$(ZLIB_LDFLAGS) \$(XAPIAN_LDFLAGS)
 EOF
diff --git a/notmuch-client.h b/notmuch-client.h
index d110648..e1efbe0 100644
--- a/notmuch-client.h
+++ b/notmuch-client.h
@@ -450,7 +450,9 @@ typedef enum dump_formats {
 int
 notmuch_database_dump (notmuch_database_t *notmuch,
 		       const char *output_file_name,
-		       const char *query_str, dump_format_t output_format);
+		       const char *query_str,
+		       dump_format_t output_format,
+		       notmuch_bool_t gzip_output);
 
 #include "command-line-arguments.h"
 #endif
diff --git a/notmuch-dump.c b/notmuch-dump.c
index 21702d7..029f90a 100644
--- a/notmuch-dump.c
+++ b/notmuch-dump.c
@@ -21,10 +21,12 @@
 #include "notmuch-client.h"
 #include "hex-escape.h"
 #include "string-util.h"
+#include <zlib.h>
+
 
 static int
-database_dump_file (notmuch_database_t *notmuch, FILE *output,
-		    const char *query_str, int output_format)
+database_dump_file (notmuch_database_t *notmuch, gzFile output,
+			const char *query_str, int output_format)
 {
     notmuch_query_t *query;
     notmuch_messages_t *messages;
@@ -69,7 +71,7 @@ database_dump_file (notmuch_database_t *notmuch, FILE *output,
 	}
 
 	if (output_format == DUMP_FORMAT_SUP) {
-	    fprintf (output, "%s (", message_id);
+	    gzprintf (output, "%s (", message_id);
 	}
 
 	for (tags = notmuch_message_get_tags (message);
@@ -78,12 +80,12 @@ database_dump_file (notmuch_database_t *notmuch, FILE *output,
 	    const char *tag_str = notmuch_tags_get (tags);
 
 	    if (! first)
-		fputs (" ", output);
+		gzputs (output, " ");
 
 	    first = 0;
 
 	    if (output_format == DUMP_FORMAT_SUP) {
-		fputs (tag_str, output);
+		gzputs (output, tag_str);
 	    } else {
 		if (hex_encode (notmuch, tag_str,
 				&buffer, &buffer_size) != HEX_SUCCESS) {
@@ -91,12 +93,12 @@ database_dump_file (notmuch_database_t *notmuch, FILE *output,
 			     tag_str);
 		    return EXIT_FAILURE;
 		}
-		fprintf (output, "+%s", buffer);
+		gzprintf (output, "+%s", buffer);
 	    }
 	}
 
 	if (output_format == DUMP_FORMAT_SUP) {
-	    fputs (")\n", output);
+	    gzputs (output, ")\n");
 	} else {
 	    if (make_boolean_term (notmuch, "id", message_id,
 				   &buffer, &buffer_size)) {
@@ -104,7 +106,7 @@ database_dump_file (notmuch_database_t *notmuch, FILE *output,
 			     message_id, strerror (errno));
 		    return EXIT_FAILURE;
 	    }
-	    fprintf (output, " -- %s\n", buffer);
+	    gzprintf (output, " -- %s\n", buffer);
 	}
 
 	notmuch_message_destroy (message);
@@ -121,24 +123,33 @@ database_dump_file (notmuch_database_t *notmuch, FILE *output,
 int
 notmuch_database_dump (notmuch_database_t *notmuch,
 		       const char *output_file_name,
-		       const char *query_str, dump_format_t output_format)
+		       const char *query_str,
+		       dump_format_t output_format,
+		       notmuch_bool_t gzip_output)
 {
-    FILE *output = stdout;
+    gzFile output;
+    const char *mode = gzip_output ? "w9" : "wT";
+
     int ret;
 
     if (output_file_name) {
-	output = fopen (output_file_name, "w");
+	output = gzopen (output_file_name, mode);
 	if (output == NULL) {
 	    fprintf (stderr, "Error opening %s for writing: %s\n",
 		     output_file_name, strerror (errno));
 	    return EXIT_FAILURE;
 	}
+    } else {
+	output = gzdopen (fileno (stdout), mode);
     }
 
     ret = database_dump_file (notmuch, output, query_str, output_format);
 
-    if (output != stdout)
-	fclose (output);
+    /* XXX check error return */
+    gzflush (output, Z_FINISH);
+
+    if (output_file_name)
+	gzclose_w (output);
 
     return ret;
 }
@@ -158,6 +169,7 @@ notmuch_dump_command (notmuch_config_t *config, int argc, char *argv[])
     int opt_index;
 
     int output_format = DUMP_FORMAT_BATCH_TAG;
+    notmuch_bool_t gzip_output = 0;
 
     notmuch_opt_desc_t options[] = {
 	{ NOTMUCH_OPT_KEYWORD, &output_format, "format", 'f',
@@ -165,6 +177,7 @@ notmuch_dump_command (notmuch_config_t *config, int argc, char *argv[])
 				  { "batch-tag", DUMP_FORMAT_BATCH_TAG },
 				  { 0, 0 } } },
 	{ NOTMUCH_OPT_STRING, &output_file_name, "output", 'o', 0  },
+	{ NOTMUCH_OPT_BOOLEAN, &gzip_output, "gzip", 'z', 0 },
 	{ 0, 0, 0, 0, 0 }
     };
 
@@ -181,7 +194,7 @@ notmuch_dump_command (notmuch_config_t *config, int argc, char *argv[])
     }
 
     ret = notmuch_database_dump (notmuch, output_file_name, query_str,
-				 output_format);
+				 output_format, gzip_output);
 
     notmuch_database_destroy (notmuch);
 
-- 
1.9.0