Re: [Qemu-devel] [PATCH V3 2/2] qemu-img: Add json output option to the info command.

["Benoît Canet" <benoit.canet@irqsave.net>]

Le Thursday 16 Aug 2012 à 11:13:05 (+0800), Wenchao Xia a écrit :
>    I was busy in coding libqblock so forgot to move forward on qemu json
> info patches, thanks for your advance.
> 
>    one suggestion:
>    how about folder all human printf into function:
> dump_human_image_info(image_info), and at the end, make the final
> output functions as mirror:
> 
> if (human) {
>     dump_human_image_info(image_info);
> } else {
>     dump_json_image_info(image_info);
> }

I will post a patch looking like this.

Benoît
> 
>   With this, information collecting and output generating were
> separated, it will be easy to do more modification if we want.
> for eg, if we want to get the string generated and write it to
> another place or pipe, we would only need to modify
> dump_human_image_info()
> 
> 
> >This additionnal --machine=json option make qemu-img info output on
> >stdout a JSON formated representation of the image informations.
> >
> >--machine=json was choosen instead of --format=json because the
> >info command already have a -f parameter.
> >
> >example:
> >{
> >     "backing-filename-format": "raw",
> >     "snapshots": [
> >         {
> >             "vm-clock-nsec": 4647590161,
> >             "name": "truc",
> >             "date-sec": 1345034924,
> >             "date-nsec": 870405000,
> >             "id": "1",
> >             "vm-state-size": 80805256
> >         },
> >         {
> >             "vm-clock-nsec": 7065282574,
> >             "name": "onx",
> >             "date-sec": 1345034927,
> >             "date-nsec": 914633000,
> >             "id": "2",
> >             "vm-state-size": 75927370
> >         },
> >         {
> >             "vm-clock-nsec": 10108695046,
> >             "name": "list",
> >             "date-sec": 1345034939,
> >             "date-nsec": 39119000,
> >             "id": "3",
> >             "vm-state-size": 75890567
> >         }
> >     ],
> >     "virtual-size": 1073741824,
> >     "filename": "./snapshot.img",
> >     "cluster-size": 65536,
> >     "format": "qcow2",
> >     "actual-size": 242614272,
> >     "backing-filename": "truc5.raw",
> >     "dirty-flag": false
> >}
> >
> >Signed-off-by: Benoit Canet <benoit@irqsave.net>
> >---
> >  Makefile   |    3 +-
> >  qemu-img.c |  133 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
> >  2 files changed, 124 insertions(+), 12 deletions(-)
> >
> >diff --git a/Makefile b/Makefile
> >index ab82ef3..9ba064b 100644
> >--- a/Makefile
> >+++ b/Makefile
> >@@ -160,7 +160,8 @@ tools-obj-y = $(oslib-obj-y) $(trace-obj-y) qemu-tool.o qemu-timer.o \
> >  	iohandler.o cutils.o iov.o async.o
> >  tools-obj-$(CONFIG_POSIX) += compatfd.o
> >
> >-qemu-img$(EXESUF): qemu-img.o $(tools-obj-y) $(block-obj-y)
> >+qemu-img$(EXESUF): qemu-img.o $(tools-obj-y) $(block-obj-y) $(qapi-obj-y) \
> >+                              qapi-visit.o qapi-types.o
> >  qemu-nbd$(EXESUF): qemu-nbd.o $(tools-obj-y) $(block-obj-y)
> >  qemu-io$(EXESUF): qemu-io.o cmd.o $(tools-obj-y) $(block-obj-y)
> >
> >diff --git a/qemu-img.c b/qemu-img.c
> >index 80cfb9b..5e20f5d 100644
> >--- a/qemu-img.c
> >+++ b/qemu-img.c
> >@@ -21,12 +21,16 @@
> >   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> >   * THE SOFTWARE.
> >   */
> >+#include "qapi-visit.h"
> >+#include "qapi/qmp-output-visitor.h"
> >+#include "qjson.h"
> >  #include "qemu-common.h"
> >  #include "qemu-option.h"
> >  #include "qemu-error.h"
> >  #include "osdep.h"
> >  #include "sysemu.h"
> >  #include "block_int.h"
> >+#include <getopt.h>
> >  #include <stdio.h>
> >
> >  #ifdef _WIN32
> >@@ -84,6 +88,7 @@ static void help(void)
> >             "  '-p' show progress of command (only certain commands)\n"
> >             "  '-S' indicates the consecutive number of bytes that must contain only zeros\n"
> >             "       for qemu-img to create a sparse image during conversion\n"
> >+           "  '-m' or '--machine' takes the format in which the output must be done (json)\n"
> >             "\n"
> >             "Parameters to check subcommand:\n"
> >             "  '-r' tries to repair any inconsistencies that are found during the check.\n"
> >@@ -1102,21 +1107,86 @@ static void dump_snapshots(BlockDriverState *bs)
> >      g_free(sn_tab);
> >  }
> >
> >+static void collect_snapshots(BlockDriverState *bs , ImageInfo *image_info)
> >+{
> >+    int i, sn_count;
> >+    QEMUSnapshotInfo *sn_tab = NULL;
> >+    SnapshotInfoList *sn_info_list, *cur_item = NULL;
> >+    sn_count = bdrv_snapshot_list(bs, &sn_tab);
> >+
> >+    for (i = 0; i < sn_count; i++) {
> >+        image_info->has_snapshots = true;
> >+        sn_info_list = g_new0(SnapshotInfoList, 1);
> >+
> >+        sn_info_list->value = g_new0(SnapshotInfo, 1);
> >+        sn_info_list->value->id = g_strdup(sn_tab[i].id_str);
> >+        sn_info_list->value->name = g_strdup(sn_tab[i].name);
> >+        sn_info_list->value->vm_state_size = sn_tab[i].vm_state_size;
> >+        sn_info_list->value->date_sec = sn_tab[i].date_sec;
> >+        sn_info_list->value->date_nsec = sn_tab[i].date_nsec;
> >+        sn_info_list->value->vm_clock_nsec = sn_tab[i].vm_clock_nsec;
> >+
> >+        /* XXX: waiting for the qapi to support GSList */
> >+        if (!cur_item) {
> >+            image_info->snapshots = cur_item = sn_info_list;
> >+        } else {
> >+            cur_item->next = sn_info_list;
> >+            cur_item = sn_info_list;
> >+        }
> >+
> >+    }
> >+
> >+    g_free(sn_tab);
> >+}
> >+
> >+static void dump_json_image_info(ImageInfo *image_info)
> >+{
> >+    Error *errp = NULL;
> >+    QString *str;
> >+    QmpOutputVisitor *ov = qmp_output_visitor_new();
> >+    QObject *obj;
> >+    visit_type_ImageInfo(qmp_output_get_visitor(ov),
> >+                         &image_info, NULL, &errp);
> >+    obj = qmp_output_get_qobject(ov);
> >+    str = qobject_to_json_pretty(obj);
> >+    assert(str != NULL);
> >+    printf("%s\n", qstring_get_str(str));
> >+    qobject_decref(obj);
> >+    qmp_output_visitor_cleanup(ov);
> >+    QDECREF(str);
> >+}
> >+
> >+#define PRINTH(human, args...) do { \
> >+    if (human) {                    \
> >+        printf(args);               \
> >+    } } while (0);
> >+
> >  static int img_info(int argc, char **argv)
> >  {
> >      int c;
> >-    const char *filename, *fmt;
> >-    BlockDriverState *bs;
> >+    bool human = true;
> >+    const char *filename, *fmt, *machine;
> >+    BlockDriverState *bs, *backing_bs = NULL;
> >      char size_buf[128], dsize_buf[128];
> >      uint64_t total_sectors;
> >      int64_t allocated_size;
> >      char backing_filename[1024];
> >      char backing_filename2[1024];
> >      BlockDriverInfo bdi;
> >+    ImageInfo *image_info;
> >
> >      fmt = NULL;
> >+    machine = NULL;
> >      for(;;) {
> >-        c = getopt(argc, argv, "f:h");
> >+        int option_index = 0;
> >+        static struct option long_options[] = {
> >+            {"help", no_argument, 0, 'h'},
> >+            {"format", required_argument, 0, 'f'},
> >+            {"machine", required_argument, 0, 'm'},
> >+            {0, 0, 0, 0}
> >+        };
> >+        c = getopt_long(argc, argv, "f:h",
> >+                        long_options, &option_index);
> >          if (c == -1) {
> >              break;
> >          }
> >@@ -1128,6 +1198,9 @@ static int img_info(int argc, char **argv)
> >          case 'f':
> >              fmt = optarg;
> >              break;
> >+        case 'm':
> >+            machine = optarg;
> >+            break;
> >          }
> >      }
> >      if (optind >= argc) {
> >@@ -1135,8 +1208,14 @@ static int img_info(int argc, char **argv)
> >      }
> >      filename = argv[optind++];
> >
> >+    image_info = g_new0(ImageInfo, 1);
> >+    if (machine && !strncmp(machine, "json", strlen("json"))) {
> >+        human = false;
> >+    }
> >+
> >      bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING);
> >      if (!bs) {
> >+        g_free(image_info);
> >          return 1;
> >      }
> >      bdrv_get_geometry(bs, &total_sectors);
> >@@ -1148,39 +1227,71 @@ static int img_info(int argc, char **argv)
> >          get_human_readable_size(dsize_buf, sizeof(dsize_buf),
> >                                  allocated_size);
> >      }
> >-    printf("image: %s\n"
> >+    PRINTH(human, "image: %s\n"
> >             "file format: %s\n"
> >             "virtual size: %s (%" PRId64 " bytes)\n"
> >             "disk size: %s\n",
> >             filename, bdrv_get_format_name(bs), size_buf,
> >             (total_sectors * 512),
> >             dsize_buf);
> >+    image_info->filename = g_strdup(filename);
> >+    image_info->format = g_strdup(bdrv_get_format_name(bs));
> >+    image_info->virtual_size = total_sectors * 512;
> >+    image_info->actual_size = allocated_size >= 0 ? allocated_size : 0;
> >      if (bdrv_is_encrypted(bs)) {
> >-        printf("encrypted: yes\n");
> >+        PRINTH(human, "encrypted: yes\n");
> >+        image_info->encrypted = true;
> >+        image_info->has_encrypted = true;
> >      }
> >      if (bdrv_get_info(bs, &bdi) >= 0) {
> >+        image_info->has_cluster_size = true;
> >+        image_info->has_dirty_flag = true;
> >          if (bdi.cluster_size != 0) {
> >-            printf("cluster_size: %d\n", bdi.cluster_size);
> >+            PRINTH(human, "cluster_size: %d\n", bdi.cluster_size);
> >+            image_info->cluster_size = bdi.cluster_size;
> >          }
> >          if (bdi.is_dirty) {
> >-            printf("cleanly shut down: no\n");
> >+            PRINTH(human, "cleanly shut down: no\n");
> >+            image_info->dirty_flag = true;
> >+        } else {
> >+            image_info->dirty_flag = false;
> >          }
> >      }
> >      bdrv_get_backing_filename(bs, backing_filename, sizeof(backing_filename));
> >      if (backing_filename[0] != '\0') {
> >          bdrv_get_full_backing_filename(bs, backing_filename2,
> >                                         sizeof(backing_filename2));
> >-        printf("backing file: %s", backing_filename);
> >+        backing_bs = bdrv_new_open(backing_filename2, fmt,
> >+                                   BDRV_O_FLAGS | BDRV_O_NO_BACKING);
> >+        image_info->backing_filename = g_strdup(backing_filename);
> >+        image_info->backing_filename_format =
> >+                    g_strdup(bdrv_get_format_name(backing_bs));
> >+        bdrv_delete(backing_bs);
> >+        PRINTH(human, "backing file: %s", backing_filename);
> >          if (strcmp(backing_filename, backing_filename2) != 0) {
> >-            printf(" (actual path: %s)", backing_filename2);
> >+            PRINTH(human, " (actual path: %s)", backing_filename2);
> >+        }
> >+        if (human) {
> >+            putchar('\n');
> >          }
> >-        putchar('\n');
> >+        image_info->has_backing_filename = true;
> >+        image_info->has_backing_filename_format = true;
> >      }
> >-    dump_snapshots(bs);
> >+
> >+    if (human) {
> >+        dump_snapshots(bs);
> >+    } else {
> >+        collect_snapshots(bs, image_info);
> >+        dump_json_image_info(image_info);
> >+    }
> >+
> >+    qapi_free_ImageInfo(image_info);
> >      bdrv_delete(bs);
> >      return 0;
> >  }
> >
> >+#undef PRINTH
> >+
> >  #define SNAPSHOT_LIST   1
> >  #define SNAPSHOT_CREATE 2
> >  #define SNAPSHOT_APPLY  3
> >
> 
> 
> -- 
> Best Regards
> 
> Wenchao Xia
>