[PATCH RFC V2 05/10] libxl_json: introduce parser functions for builtin types

[Wei Liu <wei.liu2@citrix.com>]

This changeset introduces following functions:
 * libxl_defbool_parse_json
 * libxl__bool_parse_json
 * libxl_uuid_parse_json
 * libxl_mac_parse_json
 * libxl_bitmap_parse_json
 * libxl_cpuid_policy_list_parse_json
 * libxl_string_list_parse_json
 * libxl_key_value_list_parse_json
 * libxl_hwcap_parse_json
 * libxl__integer_parse_json
 * libxl__string_parse_json

They will be used in later patch to convert the libxl__json_object
tree of a builtin type to libxl_FOO struct.

Also remove delcaration of libxl_domid_gen_json as libxl_domid uses
yajl_gen_integer to generate JSON object.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/libxl_cpuid.c   |   92 +++++++++++++++++----
 tools/libxl/libxl_json.c    |  191 +++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/libxl_json.h    |   27 +++++-
 tools/libxl/libxl_nocpuid.c |    7 ++
 4 files changed, 300 insertions(+), 17 deletions(-)

diff --git a/tools/libxl/libxl_cpuid.c b/tools/libxl/libxl_cpuid.c
index dd21b78..2c725a5 100644
--- a/tools/libxl/libxl_cpuid.c
+++ b/tools/libxl/libxl_cpuid.c
@@ -336,29 +336,29 @@ void libxl_cpuid_set(libxl_ctx *ctx, uint32_t domid,
                      (const char**)(cpuid[i].policy), cpuid_res);
 }
 
+static const char *input_names[2] = { "leaf", "subleaf" };
+static const char *policy_names[4] = { "eax", "ebx", "ecx", "edx" };
+/*
+ * Aiming for:
+ * [
+ *     { 'leaf':    'val-eax',
+ *       'subleaf': 'val-ecx',
+ *       'eax':     'filter',
+ *       'ebx':     'filter',
+ *       'ecx':     'filter',
+ *       'edx':     'filter' },
+ *     { 'leaf':    'val-eax', ..., 'eax': 'filter', ... },
+ *     ... etc ...
+ * ]
+ */
+
 yajl_gen_status libxl_cpuid_policy_list_gen_json(yajl_gen hand,
                                 libxl_cpuid_policy_list *pcpuid)
 {
     libxl_cpuid_policy_list cpuid = *pcpuid;
     yajl_gen_status s;
-    const char *input_names[2] = { "leaf", "subleaf" };
-    const char *policy_names[4] = { "eax", "ebx", "ecx", "edx" };
     int i, j;
 
-    /*
-     * Aiming for:
-     * [
-     *     { 'leaf':    'val-eax',
-     *       'subleaf': 'val-ecx',
-     *       'eax':     'filter',
-     *       'ebx':     'filter',
-     *       'ecx':     'filter',
-     *       'edx':     'filter' },
-     *     { 'leaf':    'val-eax', ..., 'eax': 'filter', ... },
-     *     ... etc ...
-     * ]
-     */
-
     s = yajl_gen_array_open(hand);
     if (s != yajl_gen_status_ok) goto out;
 
@@ -396,6 +396,66 @@ out:
     return s;
 }
 
+int libxl_cpuid_policy_list_parse_json(libxl_ctx *ctx,
+                                       const libxl__json_object *o,
+                                       libxl_cpuid_policy_list *p)
+{
+    int i, size;
+    libxl_cpuid_policy_list l;
+
+    if (!libxl__json_object_is_array(o))
+        return -1;
+
+    if (!o->u.array->count)
+        return 0;
+
+    size = o->u.array->count;
+    /* need one extra slot as setinel */
+    l = *p = calloc(size + 1, sizeof(libxl_cpuid_policy));
+
+    if (!l)
+        return -1;
+
+    memset(l, 0, sizeof(libxl_cpuid_policy) * (size + 1));
+    l[size].input[0] = XEN_CPUID_INPUT_UNUSED;
+    l[size].input[1] = XEN_CPUID_INPUT_UNUSED;
+
+    for (i = 0; i < size; i++) {
+        const libxl__json_object *t;
+        int j;
+
+        if (flexarray_get(o->u.array, i, (void**)&t) != 0)
+            return -1;          /* dispose_fn will clean up memory
+                                 * allocation */
+
+        assert(libxl__json_object_is_map(t));
+
+        for (j = 0; j < 2; j++) {
+            const libxl__json_object *r;
+
+            r = libxl__json_map_get(input_names[j], t, JSON_INTEGER);
+            if (!r)
+                l[i].input[j] = XEN_CPUID_INPUT_UNUSED;
+            else
+                l[i].input[j] = r->u.i;
+        }
+
+        for (j = 0; j < 4; j++) {
+            const libxl__json_object *r;
+
+            r = libxl__json_map_get(policy_names[j], t, JSON_STRING);
+            if (!r)
+                l[i].policy[j] = NULL;
+            else
+                l[i].policy[j] = strdup(r->u.string);
+        }
+    }
+
+    assert(i == size);
+
+    return 0;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxl/libxl_json.c b/tools/libxl/libxl_json.c
index 6f1116f..e2d5dbe 100644
--- a/tools/libxl/libxl_json.c
+++ b/tools/libxl/libxl_json.c
@@ -100,6 +100,35 @@ yajl_gen_status libxl_defbool_gen_json(yajl_gen hand,
     return libxl__yajl_gen_asciiz(hand, libxl_defbool_to_string(*db));
 }
 
+int libxl_defbool_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                             libxl_defbool *p)
+{
+    if (!libxl__json_object_is_string(o))
+        return -1;
+
+    if (!strncmp(o->u.string, "<default>", strlen("<default>")))
+        p->val = 0;
+    else if (!strncmp(o->u.string, "True", strlen("True")))
+        p->val = 1;
+    else if (!strncmp(o->u.string, "False", strlen("False")))
+        p->val = -1;
+    else
+        return -1;
+
+    return 0;
+}
+
+int libxl__bool_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                           bool *p)
+{
+    if (!libxl__json_object_is_bool(o))
+        return -1;
+
+    *p = o->u.b;
+
+    return 0;
+}
+
 yajl_gen_status libxl_uuid_gen_json(yajl_gen hand,
                                     libxl_uuid *uuid)
 {
@@ -108,6 +137,15 @@ yajl_gen_status libxl_uuid_gen_json(yajl_gen hand,
     return yajl_gen_string(hand, (const unsigned char *)buf, LIBXL_UUID_FMTLEN);
 }
 
+int libxl_uuid_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                          libxl_uuid *p)
+{
+    if (!libxl__json_object_is_string(o))
+        return -1;
+
+    return libxl_uuid_from_string(p, o->u.string);
+}
+
 yajl_gen_status libxl_bitmap_gen_json(yajl_gen hand,
                                       libxl_bitmap *bitmap)
 {
@@ -128,6 +166,34 @@ out:
     return s;
 }
 
+int libxl_bitmap_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                            libxl_bitmap *p)
+{
+    int i;
+    int size;
+    const libxl__json_object *t;
+
+    if (!libxl__json_object_is_array(o))
+        return -1;
+
+    if (!o->u.array->count)
+        return 0;
+
+    t = libxl__json_array_get(o, o->u.array->count - 1);
+    size = t->u.i + 1;
+
+    libxl_bitmap_alloc(ctx, p, size);
+
+    for (i = 0; (t = libxl__json_array_get(o, i)); i++) {
+        if (!libxl__json_object_is_integer(t))
+            return -1;          /* dispose_fn will clean up memory
+                                 * allocation */
+        libxl_bitmap_set(p, t->u.i);
+    }
+
+    return 0;
+}
+
 yajl_gen_status libxl_key_value_list_gen_json(yajl_gen hand,
                                               libxl_key_value_list *pkvl)
 {
@@ -155,6 +221,43 @@ out:
     return s;
 }
 
+int libxl_key_value_list_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                                    libxl_key_value_list *p)
+{
+    libxl__json_map_node *node = NULL;
+    flexarray_t *maps = NULL;
+    int i, size;
+    libxl_key_value_list kvl;
+
+    if (!libxl__json_object_is_map(o))
+        return -1;
+
+    maps = o->u.map;
+    size = maps->count * 2;
+    kvl = *p = calloc(size, sizeof(char *));
+    if (!kvl)
+        return -1;
+
+    memset(kvl, 0, sizeof(char *) * size);
+
+    for (i = 0; i < maps->count; i++) {
+        int idx = i * 2;
+        if (flexarray_get(maps, i, (void**)&node) != 0)
+            return -1;
+        assert(libxl__json_object_is_string(node->obj) ||
+               libxl__json_object_is_null(node->obj));
+        kvl[idx]   = strdup(node->map_key);
+        if (libxl__json_object_is_string(node->obj))
+            kvl[idx+1] = strdup(node->obj->u.string);
+        else
+            kvl[idx+1] = NULL;
+    }
+
+    assert(i == maps->count);
+
+    return 0;
+}
+
 yajl_gen_status libxl_string_list_gen_json(yajl_gen hand, libxl_string_list *pl)
 {
     libxl_string_list l = *pl;
@@ -176,6 +279,36 @@ out:
     return s;
 }
 
+int libxl_string_list_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                                 libxl_string_list *p)
+{
+    const libxl__json_object *t;
+    libxl_string_list l;
+    flexarray_t *array = NULL;
+    int i, size;
+
+    if (!libxl__json_object_is_array(o))
+        return -1;
+
+    array = o->u.array;
+    size = array->count;
+    /* need one extra slot as sentinel */
+    l = *p = calloc(size + 1, sizeof(char *));
+
+    if (!l)
+        return -1;
+
+    memset(l, 0, sizeof(char *) * size);
+    l[size] = NULL;
+
+    for (i = 0; (t = libxl__json_array_get(o, i)); i++) {
+        assert(libxl__json_object_is_string(t));
+        l[i] = strdup(t->u.string);
+    }
+
+    return 0;
+}
+
 yajl_gen_status libxl_mac_gen_json(yajl_gen hand, libxl_mac *mac)
 {
     char buf[LIBXL_MAC_FMTLEN+1];
@@ -183,6 +316,15 @@ yajl_gen_status libxl_mac_gen_json(yajl_gen hand, libxl_mac *mac)
     return yajl_gen_string(hand, (const unsigned char *)buf, LIBXL_MAC_FMTLEN);
 }
 
+int libxl_mac_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                         libxl_mac *p)
+{
+    if (!libxl__json_object_is_string(o))
+        return -1;
+
+    return libxl__parse_mac(o->u.string, *p);
+}
+
 yajl_gen_status libxl_hwcap_gen_json(yajl_gen hand,
                                      libxl_hwcap *p)
 {
@@ -201,6 +343,27 @@ out:
     return s;
 }
 
+int libxl_hwcap_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                           libxl_hwcap *p)
+{
+    int i;
+
+    if (!libxl__json_object_is_array(o))
+        return -1;
+
+    for (i = 0; i<4; i++) {
+        const libxl__json_object *t;
+
+        t = libxl__json_array_get(o, i);
+        if (!t || !libxl__json_object_is_integer(t))
+            return -1;
+
+        (*p)[i] = t->u.i;
+    }
+
+    return 0;
+}
+
 yajl_gen_status libxl__string_gen_json(yajl_gen hand,
                                        const char *p)
 {
@@ -210,6 +373,23 @@ yajl_gen_status libxl__string_gen_json(yajl_gen hand,
         return yajl_gen_null(hand);
 }
 
+int libxl__string_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                             char **p)
+{
+    if (!libxl__json_object_is_string(o) && !libxl__json_object_is_null(o))
+        return -1;
+
+    if (libxl__json_object_is_null(o)) {
+        *p = NULL;
+    } else {
+        *p = strdup(o->u.string);
+        if (!*p)
+            return -1;
+    }
+
+    return 0;
+}
+
 /*
  * libxl__json_object helper functions
  */
@@ -824,6 +1004,17 @@ out:
     return rc;
 }
 
+int libxl__integer_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                              void *p)
+{
+    if (!libxl__json_object_is_integer(o))
+        return -1;
+
+    *((long long *)p) = o->u.i;
+
+    return 0;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxl/libxl_json.h b/tools/libxl/libxl_json.h
index a4dd8fc..d7bdeb5 100644
--- a/tools/libxl/libxl_json.h
+++ b/tools/libxl/libxl_json.h
@@ -22,17 +22,42 @@
 #  include <yajl/yajl_version.h>
 #endif
 
+typedef struct libxl__json_object libxl__json_object;
+
 yajl_gen_status libxl_defbool_gen_json(yajl_gen hand, libxl_defbool *p);
-yajl_gen_status libxl_domid_gen_json(yajl_gen hand, libxl_domid *p);
+int libxl_defbool_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                             libxl_defbool *p);
+int libxl__bool_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                           bool *p);
 yajl_gen_status libxl_uuid_gen_json(yajl_gen hand, libxl_uuid *p);
+int libxl_uuid_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                          libxl_uuid *p);
 yajl_gen_status libxl_mac_gen_json(yajl_gen hand, libxl_mac *p);
+int libxl_mac_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                         libxl_mac *p);
 yajl_gen_status libxl_bitmap_gen_json(yajl_gen hand, libxl_bitmap *p);
+int libxl_bitmap_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                            libxl_bitmap *p);
 yajl_gen_status libxl_cpuid_policy_list_gen_json(yajl_gen hand,
                                                  libxl_cpuid_policy_list *p);
+int libxl_cpuid_policy_list_parse_json(libxl_ctx *ctx,
+                                       const libxl__json_object *o,
+                                       libxl_cpuid_policy_list *p);
 yajl_gen_status libxl_string_list_gen_json(yajl_gen hand, libxl_string_list *p);
+int libxl_string_list_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                                 libxl_string_list *p);
 yajl_gen_status libxl_key_value_list_gen_json(yajl_gen hand,
                                               libxl_key_value_list *p);
+int libxl_key_value_list_parse_json(libxl_ctx *ctx,
+                                    const libxl__json_object *o,
+                                    libxl_key_value_list *p);
 yajl_gen_status libxl_hwcap_gen_json(yajl_gen hand, libxl_hwcap *p);
+int libxl_hwcap_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                           libxl_hwcap *p);
+int libxl__integer_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                              void *p);
+int libxl__string_parse_json(libxl_ctx *ctx, const libxl__json_object *o,
+                             char **p);
 
 #include <_libxl_types_json.h>
 
diff --git a/tools/libxl/libxl_nocpuid.c b/tools/libxl/libxl_nocpuid.c
index 5f7cb6a..7364dd5 100644
--- a/tools/libxl/libxl_nocpuid.c
+++ b/tools/libxl/libxl_nocpuid.c
@@ -44,6 +44,13 @@ yajl_gen_status libxl_cpuid_policy_list_gen_json(yajl_gen hand,
     return 0;
 }
 
+int libxl_cpuid_policy_list_parse_json(libxl_ctx *ctx,
+                                       const libxl__json_object *o,
+                                       libxl_cpuid_policy_list *p)
+{
+    return 0;
+}
+
 /*
  * Local variables:
  * mode: C
-- 
1.7.10.4