[Qemu-devel] [PATCH] let qemu-img info genereate json output

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

  This patch would add option -j in qemu-img info command, which
would generate json output in stdout.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
---
 qemu-img.c |  306 +++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 files changed, 264 insertions(+), 42 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index 80cfb9b..a514c17 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -33,6 +33,9 @@
 #include <windows.h>
 #endif
 
+#include "qint.h"
+#include "qjson.h"
+
 typedef struct img_cmd_t {
     const char *name;
     int (*handler)(int argc, char **argv);
@@ -84,6 +87,7 @@ 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"
+           "  '-j' try get json output, which would be in stdout, only valid in info command\n"
            "\n"
            "Parameters to check subcommand:\n"
            "  '-r' tries to repair any inconsistencies that are found during the check.\n"
@@ -1102,21 +1106,210 @@ static void dump_snapshots(BlockDriverState *bs)
     g_free(sn_tab);
 }
 
+/* string must be allocated on heap */
+struct img_infos {
+    char *filename;
+    char *fmt;
+    uint64_t total_sectors;
+    int64_t allocated_size;
+    int32 enc_flag;
+    BlockDriverInfo *bdi;
+    char *backing_filename;
+    char *backing_filename_full;
+    QEMUSnapshotInfo *sn_tab;
+    int nb_sns;
+};
+
+static void img_infos_init(struct img_infos *pinfo)
+{
+    memset(pinfo, 0, sizeof(struct img_infos));
+}
+
+#define TRY_FREE(p) { \
+    if ((p) != NULL) { \
+        g_free((p)); \
+        (p) = NULL; \
+    } \
+}
+static void img_infos_uninit(struct img_infos *pinfo)
+{
+    TRY_FREE(pinfo->filename);
+    TRY_FREE(pinfo->fmt);
+    TRY_FREE(pinfo->bdi);
+    TRY_FREE(pinfo->backing_filename);
+    TRY_FREE(pinfo->backing_filename_full);
+    TRY_FREE(pinfo->sn_tab);
+}
+
+static void snapshot_info_to_list(QList *qlist, QEMUSnapshotInfo *sn)
+{
+    char buf[128];
+    QInt *qint;
+    QString *qstr;
+    QDict *qdic = qdict_new();
+
+    qstr = qstring_from_str(sn->id_str);
+    qdict_put_obj(qdic, "id", QOBJECT(qstr));
+    qstr = qstring_from_str(sn->name);
+    qdict_put_obj(qdic, "name", QOBJECT(qstr));
+
+    snprintf(buf, sizeof(buf), "%ld", sn->vm_state_size);
+    qstr = qstring_from_str(buf);
+    qdict_put_obj(qdic, "vm_state_size", QOBJECT(qstr));
+
+    qint = qint_from_int(sn->date_sec);
+    qdict_put_obj(qdic, "date_sec", QOBJECT(qint));
+    qint = qint_from_int(sn->date_nsec);
+    qdict_put_obj(qdic, "date_nsec", QOBJECT(qint));
+    snprintf(buf, sizeof(buf), "%ld", sn->vm_clock_nsec);
+    qstr = qstring_from_str(buf);
+    qdict_put_obj(qdic, "vm_clock_nsec", QOBJECT(qstr));
+    qlist_append(qlist, qdic);
+}
+
+static void img_infos_print_json(struct img_infos *pinfo, int ret)
+{
+    char buf[128];
+    QInt *qint;
+    QDict *qdic, *qdic_all;
+    QString *qstr;
+    QList *qlist;
+    int i;
+
+    qdic_all = qdict_new();
+
+    qint = qint_from_int(ret);
+    qdict_put_obj(qdic_all, "return", QOBJECT(qint));
+    if (ret != 0) {
+        goto print;
+    }
+
+    qdic = qdict_new();
+    if (pinfo->filename != NULL) {
+        qstr = qstring_from_str(pinfo->filename);
+        qdict_put_obj(qdic, "filename", QOBJECT(qstr));
+    }
+    if (pinfo->fmt != NULL) {
+        qstr = qstring_from_str(pinfo->fmt);
+        qdict_put_obj(qdic, "fmt", QOBJECT(qstr));
+    }
+    snprintf(buf, sizeof(buf), "%ld", pinfo->total_sectors * 512);
+    qstr = qstring_from_str(buf);
+    qdict_put_obj(qdic, "virtual_size", QOBJECT(qstr));
+    snprintf(buf, sizeof(buf), "%ld", pinfo->allocated_size);
+    qstr = qstring_from_str(buf);
+    qdict_put_obj(qdic, "actual_size", QOBJECT(qstr));
+    qint = qint_from_int(pinfo->enc_flag);
+    qdict_put_obj(qdic, "encrypted", QOBJECT(qint));
+
+    if (pinfo->bdi != NULL) {
+        qint = qint_from_int(pinfo->bdi->cluster_size);
+        qdict_put_obj(qdic, "cluster_size", QOBJECT(qint));
+        qint = qint_from_int(pinfo->bdi->is_dirty);
+        qdict_put_obj(qdic, "dirty_flag", QOBJECT(qint));
+    }
+
+    if (pinfo->backing_filename != NULL) {
+        qstr = qstring_from_str(pinfo->backing_filename);
+        qdict_put_obj(qdic, "backing_filename", QOBJECT(qstr));
+        if ((pinfo->backing_filename != NULL) &&
+            (0 != strcmp(pinfo->backing_filename,
+                         pinfo->backing_filename_full))
+           ) {
+                qstr = qstring_from_str(pinfo->backing_filename_full);
+                qdict_put_obj(qdic, "backing_filename_full", QOBJECT(qstr));
+        }
+    }
+
+    qlist = qlist_new();
+    i = 0;
+    while (i < pinfo->nb_sns) {
+        snapshot_info_to_list(qlist,  &(pinfo->sn_tab[i]));
+        i++;
+    }
+    qdict_put_obj(qdic, "snapshot_list", QOBJECT(qlist));
+
+    qdict_put_obj(qdic_all, "information", QOBJECT(qdic));
+
+ print:
+    qstr = qobject_to_json_pretty(QOBJECT(qdic_all));
+    printf("%s\n", qstring_get_str(qstr));
+    qobject_decref(QOBJECT(qstr));
+
+    qobject_decref(QOBJECT(qdic_all));
+}
+
+static void img_infos_print(struct img_infos *pinfo)
+{
+    char size_buf[128], dsize_buf[128], buf[256];
+    int i;
+    QEMUSnapshotInfo *sn;
+
+    get_human_readable_size(size_buf, sizeof(size_buf),
+                                      pinfo->total_sectors * 512);
+    if (pinfo->allocated_size < 0) {
+        snprintf(dsize_buf, sizeof(dsize_buf), "unavailable");
+    } else {
+        get_human_readable_size(dsize_buf, sizeof(dsize_buf),
+                                pinfo->allocated_size);
+    }
+
+    printf("image: %s\n"
+           "file format: %s\n"
+           "virtual size: %s (%" PRId64 " bytes)\n"
+           "disk size: %s\n",
+           pinfo->filename, pinfo->fmt, size_buf,
+           (pinfo->total_sectors * 512),
+           dsize_buf);
+
+    if (pinfo->enc_flag > 0) {
+        printf("encrypted: yes\n");
+    }
+
+    if (pinfo->bdi != NULL) {
+        if (pinfo->bdi->cluster_size != 0) {
+            printf("cluster_size: %d\n", pinfo->bdi->cluster_size);
+        }
+        if (pinfo->bdi->is_dirty) {
+            printf("cleanly shut down: no\n");
+        }
+    }
+
+    if (pinfo->backing_filename != NULL) {
+        printf("backing file: %s", pinfo->backing_filename);
+        if ((pinfo->backing_filename != NULL) &&
+            (0 != strcmp(pinfo->backing_filename,
+                         pinfo->backing_filename_full))
+           ) {
+            printf(" (actual path: %s)", pinfo->backing_filename_full);
+        }
+        putchar('\n');
+    }
+
+    if (pinfo->nb_sns <= 0) {
+        return;
+    }
+
+    printf("Snapshot list:\n");
+    printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), NULL));
+    for (i = 0; i < pinfo->nb_sns; i++) {
+        sn = &(pinfo->sn_tab[i]);
+        printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), sn));
+    }
+}
+
+#define FILENAME_LEN_MAX (1024)
 static int img_info(int argc, char **argv)
 {
     int c;
     const char *filename, *fmt;
     BlockDriverState *bs;
-    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;
+    int json_flag = 0, ret = 0;
+    struct img_infos my_img_infos;
 
     fmt = NULL;
     for(;;) {
-        c = getopt(argc, argv, "f:h");
+        c = getopt(argc, argv, "f:h:j");
         if (c == -1) {
             break;
         }
@@ -1128,6 +1321,9 @@ static int img_info(int argc, char **argv)
         case 'f':
             fmt = optarg;
             break;
+        case 'j':
+            json_flag = 1;
+            break;
         }
     }
     if (optind >= argc) {
@@ -1135,50 +1331,76 @@ static int img_info(int argc, char **argv)
     }
     filename = argv[optind++];
 
+    img_infos_init(&my_img_infos);
+    my_img_infos.filename = strdup(filename);
+
     bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING);
     if (!bs) {
-        return 1;
+        ret = 1;
+        goto output;
     }
-    bdrv_get_geometry(bs, &total_sectors);
-    get_human_readable_size(size_buf, sizeof(size_buf), total_sectors * 512);
-    allocated_size = bdrv_get_allocated_file_size(bs);
-    if (allocated_size < 0) {
-        snprintf(dsize_buf, sizeof(dsize_buf), "unavailable");
-    } else {
-        get_human_readable_size(dsize_buf, sizeof(dsize_buf),
-                                allocated_size);
+
+    my_img_infos.fmt = strdup(bdrv_get_format_name(bs));
+
+    bdrv_get_geometry(bs, &(my_img_infos.total_sectors));
+    my_img_infos.allocated_size = bdrv_get_allocated_file_size(bs);
+
+    my_img_infos.enc_flag = bdrv_is_encrypted(bs);
+    my_img_infos.bdi = g_malloc(sizeof(BlockDriverInfo));
+    if (my_img_infos.bdi == NULL) {
+        ret = -1;
+        goto output;
     }
-    printf("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);
-    if (bdrv_is_encrypted(bs)) {
-        printf("encrypted: yes\n");
+    if (bdrv_get_info(bs, my_img_infos.bdi) < 0) {
+        g_free(my_img_infos.bdi);
+        my_img_infos.bdi = NULL;
     }
-    if (bdrv_get_info(bs, &bdi) >= 0) {
-        if (bdi.cluster_size != 0) {
-            printf("cluster_size: %d\n", bdi.cluster_size);
+
+    my_img_infos.backing_filename = g_malloc(FILENAME_LEN_MAX);
+    if (my_img_infos.backing_filename == NULL) {
+        ret = -1;
+        goto output;
+    }
+    memset(my_img_infos.backing_filename, 0, FILENAME_LEN_MAX);
+    bdrv_get_backing_filename(bs, my_img_infos.backing_filename,
+                                                   FILENAME_LEN_MAX);
+    if (my_img_infos.backing_filename[0] != '\0') {
+        my_img_infos.backing_filename_full = g_malloc(FILENAME_LEN_MAX);
+        if (my_img_infos.backing_filename_full == NULL) {
+            ret = -1;
+            goto output;
         }
-        if (bdi.is_dirty) {
-            printf("cleanly shut down: no\n");
+        memset(my_img_infos.backing_filename_full, 0, FILENAME_LEN_MAX);
+        bdrv_get_full_backing_filename(bs, my_img_infos.backing_filename_full,
+                                       FILENAME_LEN_MAX);
+        if (my_img_infos.backing_filename_full[0] == '\0') {
+            g_free(my_img_infos.backing_filename_full);
+            my_img_infos.backing_filename_full = NULL;
         }
+    } else {
+        g_free(my_img_infos.backing_filename);
+        my_img_infos.backing_filename = NULL;
     }
-    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);
-        if (strcmp(backing_filename, backing_filename2) != 0) {
-            printf(" (actual path: %s)", backing_filename2);
-        }
-        putchar('\n');
+
+    my_img_infos.nb_sns = bdrv_snapshot_list(bs, &(my_img_infos.sn_tab));
+
+ output:
+    if ((ret != 0) && (json_flag == 0)) {
+        goto clean;
     }
-    dump_snapshots(bs);
-    bdrv_delete(bs);
-    return 0;
+
+    if (json_flag > 0) {
+        img_infos_print_json(&my_img_infos, ret);
+    } else {
+        img_infos_print(&my_img_infos);
+    }
+
+ clean:
+    if (bs != NULL) {
+        bdrv_delete(bs);
+    }
+    img_infos_uninit(&my_img_infos);
+    return ret;
 }
 
 #define SNAPSHOT_LIST   1
-- 
1.7.1