[Libguestfs] [PATCH v5 01/10] lib/osinfo.c: Extract xml processing into a callback
Cédric Bosdonnat
cbosdonnat at suse.com
Thu Mar 23 09:02:39 UTC 2017
In order to further reuse the osinfo database parsing in OCAML, this
commit extracts the XML processing for the distro ISOs and places it
into a newly created callback.
This will later help other code to traverse the osinfo DB files and
let them extract what they need from them.
---
lib/osinfo.c | 80 +++++++++++++++++++++++++++++-------------------------------
1 file changed, 39 insertions(+), 41 deletions(-)
diff --git a/lib/osinfo.c b/lib/osinfo.c
index ea2a7659a..3514585c7 100644
--- a/lib/osinfo.c
+++ b/lib/osinfo.c
@@ -52,6 +52,7 @@
#include <string.h>
#include <unistd.h>
#include <dirent.h>
+#include <errno.h>
#include <assert.h>
#include <sys/types.h>
#include <libintl.h>
@@ -71,10 +72,11 @@ gl_lock_define_initialized (static, osinfo_db_lock);
static ssize_t osinfo_db_size = 0; /* 0 = unread, -1 = error, >= 1 = #records */
static struct osinfo *osinfo_db = NULL;
-static int read_osinfo_db (guestfs_h *g);
-static void free_osinfo_db_entry (struct osinfo *);
-
#define XMLSTREQ(a,b) (xmlStrEqual((a),(b)) == 1)
+typedef int (*read_osinfo_db_callback) (guestfs_h *g, const char *path, void *opaque);
+
+static int read_osinfo_db (guestfs_h *g, read_osinfo_db_callback callback, void *opaque);
+static void free_osinfo_db_entry (struct osinfo *);
/* Given one or more fields from the header of a CD/DVD/ISO, look up
* the media in the libosinfo database and return our best guess for
@@ -87,14 +89,24 @@ static void free_osinfo_db_entry (struct osinfo *);
*/
int
guestfs_int_osinfo_map (guestfs_h *g, const struct guestfs_isoinfo *isoinfo,
- const struct osinfo **osinfo_ret)
+ const struct osinfo **osinfo_ret)
{
size_t i;
/* We only need to lock the database when reading it for the first time. */
gl_lock_lock (osinfo_db_lock);
if (osinfo_db_size == 0) {
- if (read_osinfo_db (g) == -1) {
+ if (read_osinfo_db (g, read_osinfo_db_xml, NULL) == -1) {
+ /* Fatal error: free any database entries which have been read, and
+ * mark the database as having a permanent error.
+ */
+ if (osinfo_db_size > 0) {
+ for (i = 0; i < (size_t) osinfo_db_size; ++i)
+ free_osinfo_db_entry (&osinfo_db[i]);
+ }
+ free (osinfo_db);
+ osinfo_db = NULL;
+ osinfo_db_size = -1;
gl_lock_unlock (osinfo_db_lock);
return -1;
}
@@ -156,19 +168,16 @@ guestfs_int_osinfo_map (guestfs_h *g, const struct guestfs_isoinfo *isoinfo,
* Try to use the shared osinfo database layout (and location) first:
* https://gitlab.com/libosinfo/libosinfo/blob/master/docs/database-layout.txt
*/
-static int read_osinfo_db_xml (guestfs_h *g, const char *filename);
-
-static int read_osinfo_db_flat (guestfs_h *g, const char *directory);
-static int read_osinfo_db_three_levels (guestfs_h *g, const char *directory);
-static int read_osinfo_db_directory (guestfs_h *g, const char *directory);
+static int read_osinfo_db_xml (guestfs_h *g, const char *pathname, void *data);
+static int read_osinfo_db_flat (guestfs_h *g, const char *directory, read_osinfo_db_callback callback, void *opaque);
+static int read_osinfo_db_three_levels (guestfs_h *g, const char *directory, read_osinfo_db_callback callback, void *opaque);
+static int read_osinfo_db_directory (guestfs_h *g, const char *directory, read_osinfo_db_callback callback, void *opaque);
static int
-read_osinfo_db (guestfs_h *g)
+read_osinfo_db (guestfs_h *g,
+ read_osinfo_db_callback callback, void *opaque)
{
int r;
- size_t i;
-
- assert (osinfo_db_size == 0);
/* (1) Try the shared osinfo directory, using either the
* $OSINFO_SYSTEM_DIR envvar or its default value.
@@ -181,59 +190,47 @@ read_osinfo_db (guestfs_h *g)
if (path == NULL)
path = "/usr/share/osinfo";
os_path = safe_asprintf (g, "%s/os", path);
- r = read_osinfo_db_three_levels (g, os_path);
+ r = read_osinfo_db_three_levels (g, os_path, callback, opaque);
}
if (r == -1)
- goto error;
+ return -1;
else if (r == 1)
return 0;
/* (2) Try the libosinfo directory, using the newer three-directory
* layout ($LIBOSINFO_DB_PATH / "os" / $group-ID / [file.xml]).
*/
- r = read_osinfo_db_three_levels (g, LIBOSINFO_DB_PATH "/os");
+ r = read_osinfo_db_three_levels (g, LIBOSINFO_DB_PATH "/os", callback, opaque);
if (r == -1)
- goto error;
+ return -1;
else if (r == 1)
return 0;
/* (3) Try the libosinfo directory, using the old flat directory
* layout ($LIBOSINFO_DB_PATH / "oses" / [file.xml]).
*/
- r = read_osinfo_db_flat (g, LIBOSINFO_DB_PATH "/oses");
+ r = read_osinfo_db_flat (g, LIBOSINFO_DB_PATH "/oses", callback, opaque);
if (r == -1)
- goto error;
+ return -1;
else if (r == 1)
return 0;
/* Nothing found. */
return 0;
-
- error:
- /* Fatal error: free any database entries which have been read, and
- * mark the database as having a permanent error.
- */
- if (osinfo_db_size > 0) {
- for (i = 0; i < (size_t) osinfo_db_size; ++i)
- free_osinfo_db_entry (&osinfo_db[i]);
- }
- free (osinfo_db);
- osinfo_db = NULL;
- osinfo_db_size = -1;
-
- return -1;
}
static int
-read_osinfo_db_flat (guestfs_h *g, const char *directory)
+read_osinfo_db_flat (guestfs_h *g, const char *directory,
+ read_osinfo_db_callback callback, void *opaque)
{
debug (g, "osinfo: loading flat database from %s", directory);
- return read_osinfo_db_directory (g, directory);
+ return read_osinfo_db_directory (g, directory, callback, opaque);
}
static int
-read_osinfo_db_three_levels (guestfs_h *g, const char *directory)
+read_osinfo_db_three_levels (guestfs_h *g, const char *directory,
+ read_osinfo_db_callback callback, void *opaque)
{
DIR *dir;
int r;
@@ -259,7 +256,7 @@ read_osinfo_db_three_levels (guestfs_h *g, const char *directory)
/* Iterate only on directories. */
if (stat (pathname, &sb) == 0 && S_ISDIR (sb.st_mode)) {
- r = read_osinfo_db_directory (g, pathname);
+ r = read_osinfo_db_directory (g, pathname, callback, opaque);
if (r == -1)
goto error;
}
@@ -289,7 +286,8 @@ read_osinfo_db_three_levels (guestfs_h *g, const char *directory)
}
static int
-read_osinfo_db_directory (guestfs_h *g, const char *directory)
+read_osinfo_db_directory (guestfs_h *g, const char *directory,
+ read_osinfo_db_callback callback, void *opaque)
{
DIR *dir;
int r;
@@ -311,7 +309,7 @@ read_osinfo_db_directory (guestfs_h *g, const char *directory)
CLEANUP_FREE char *pathname = NULL;
pathname = safe_asprintf (g, "%s/%s", directory, d->d_name);
- r = read_osinfo_db_xml (g, pathname);
+ r = callback (g, pathname, opaque);
if (r == -1)
goto error;
}
@@ -348,7 +346,7 @@ static int read_os_node (guestfs_h *g, xmlXPathContextPtr xpathCtx, xmlNodePtr o
* Only memory allocation failures are fatal errors here.
*/
static int
-read_osinfo_db_xml (guestfs_h *g, const char *pathname)
+read_osinfo_db_xml (guestfs_h *g, const char *pathname, void *opaque)
{
CLEANUP_XMLFREEDOC xmlDocPtr doc = NULL;
CLEANUP_XMLXPATHFREECONTEXT xmlXPathContextPtr xpathCtx = NULL;
--
2.12.0
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