1:38 p.m.
This refactoring simply changes the code so that the extent callback
builds up a list of extents (using a vector of uint32_t) and then
there is a separate function to print, instead of the callback doing
the printing. This will make coalescing of entries -- next commit --
easier to implement.
---
info/nbdinfo.c | 78 +++++++++++++++++++++++++++++++++-----------------
1 file changed, 52 insertions(+), 26 deletions(-)
diff --git a/info/nbdinfo.c b/info/nbdinfo.c
index 532f7d4..088d673 100644
--- a/info/nbdinfo.c
+++ b/info/nbdinfo.c
@@ -28,6 +28,7 @@
#include <getopt.h>
#include <limits.h>
#include <errno.h>
+#include <assert.h>
#include <libnbd.h>
@@ -52,6 +53,8 @@ struct export {
DEFINE_VECTOR_TYPE (exports, struct export)
static exports export_list = empty_vector;
+DEFINE_VECTOR_TYPE (uint32_vector, uint32_t)
+
static int collect_context (void *opaque, const char *name);
static int collect_export (void *opaque, const char *name,
const char *desc);
@@ -64,6 +67,7 @@ static int extent_callback (void *user_data, const char *metacontext,
uint64_t offset,
uint32_t *entries, size_t nr_entries,
int *error);
+static void print_extents (uint32_vector *entries);
static void __attribute__((noreturn))
usage (FILE *fp, int exitcode)
@@ -269,7 +273,9 @@ main (int argc, char *argv[])
fprintf (fp, "%" PRIi64 "\n", size);
}
else if (map) { /* --map (!list_all) */
- uint64_t offset, prev_offset, align, max_len;
+ uint32_vector entries = empty_vector;
+ uint64_t offset, align, max_len;
+ size_t prev_entries_size;
/* Did we get the requested map? */
if (!nbd_can_meta_context (nbd, map)) {
@@ -287,26 +293,28 @@ main (int argc, char *argv[])
exit (EXIT_FAILURE);
}
- if (json_output) fprintf (fp, "[\n");
for (offset = 0; offset < size;) {
- prev_offset = offset;
+ prev_entries_size = entries.size;
if (nbd_block_status (nbd, MIN (size - offset, max_len), offset,
(nbd_extent_callback) { .callback = extent_callback,
- .user_data = &offset },
+ .user_data = &entries },
0) == -1) {
fprintf (stderr, "%s: %s\n", progname, nbd_get_error ());
exit (EXIT_FAILURE);
}
- /* We expect extent_callback to increment the offset. If it did
- * not then probably the server is not returning any extents.
- */
- if (offset <= prev_offset) {
+ /* We expect extent_callback to add at least one extent to entries. */
+ if (prev_entries_size == entries.size) {
fprintf (stderr, "%s: --map: server did not return any extents\n",
progname);
exit (EXIT_FAILURE);
}
+ assert ((entries.size & 1) == 0);
+ for (i = prev_entries_size; i < entries.size; i += 2)
+ offset += entries.ptr[i];
}
- if (json_output) fprintf (fp, "\n]\n");
+
+ print_extents (&entries);
+ free (entries.ptr);
}
else { /* not --size or --map */
/* Print per-connection fields. */
@@ -741,6 +749,30 @@ get_content (struct nbd_handle *nbd, int64_t size)
}
/* Callback handling --map. */
+static int
+extent_callback (void *user_data, const char *metacontext,
+ uint64_t offset,
+ uint32_t *entries, size_t nr_entries,
+ int *error)
+{
+ uint32_vector *list = user_data;
+ size_t i;
+
+ if (strcmp (metacontext, map) != 0)
+ return 0;
+
+ /* Just append the entries we got to the list. They are printed in
+ * print_extents below.
+ */
+ for (i = 0; i < nr_entries; ++i) {
+ if (uint32_vector_append (list, entries[i]) == -1) {
+ perror ("realloc");
+ exit (EXIT_FAILURE);
+ }
+ }
+ return 0;
+}
+
static const char *
extent_description (const char *metacontext, uint32_t type)
{
@@ -769,28 +801,23 @@ extent_description (const char *metacontext, uint32_t type)
return NULL; /* Don't know - description field will be omitted. */
}
-static int
-extent_callback (void *user_data, const char *metacontext,
- uint64_t offset,
- uint32_t *entries, size_t nr_entries,
- int *error)
+static void
+print_extents (uint32_vector *entries)
{
+ uint64_t offset = 0;
size_t i;
- uint64_t *ret_offset = user_data;
- static bool comma = false;
+ bool comma = false;
- if (strcmp (metacontext, map) != 0)
- return 0;
+ if (json_output) fprintf (fp, "[\n");
- /* Print the entries received. */
- for (i = 0; i < nr_entries; i += 2) {
- const char *descr = extent_description (map, entries[i+1]);
+ for (i = 0; i < entries->size; i += 2) {
+ const char *descr = extent_description (map, entries->ptr[i+1]);
if (!json_output) {
fprintf (fp, "%10" PRIu64 " "
"%10" PRIu32 " "
"%3" PRIu32,
- offset, entries[i], entries[i+1]);
+ offset, entries->ptr[i], entries->ptr[i+1]);
if (descr)
fprintf (fp, " %s", descr);
fprintf (fp, "\n");
@@ -802,7 +829,7 @@ extent_callback (void *user_data, const char *metacontext,
fprintf (fp, "{ \"offset\": %" PRIu64 ", "
"\"length\": %" PRIu32 ", "
"\"type\": %" PRIu32,
- offset, entries[i], entries[i+1]);
+ offset, entries->ptr[i], entries->ptr[i+1]);
if (descr) {
fprintf (fp, ", \"description\": ");
print_json_string (descr);
@@ -811,9 +838,8 @@ extent_callback (void *user_data, const char *metacontext,
comma = true;
}
- offset += entries[i];
+ offset += entries->ptr[i];
}
- *ret_offset = offset;
- return 0;
+ if (json_output) fprintf (fp, "\n]\n");
}
--
2.29.0.rc2