[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v2 01/10] qdict: implement a qdict_crumple method fo
From: |
Daniel P. Berrange |
Subject: |
[Qemu-devel] [PATCH v2 01/10] qdict: implement a qdict_crumple method for un-flattening a dict |
Date: |
Mon, 7 Mar 2016 15:43:20 +0000 |
The qdict_flatten() method will take a dict whose elements are
further nested dicts/lists and flatten them by concatenating
keys.
The qdict_crumple() method aims to do the reverse, taking a flat
qdict, and turning it into a set of nested dicts/lists. It will
apply nesting based on the key name, with a '.' indicating a
new level in the hierarchy. If the keys in the nested structure
are all numeric, it will create a list, otherwise it will create
a dict.
If the keys are a mixture of numeric and non-numeric, or the
numeric keys are not in strictly ascending order, an error will
be reported.
As an example, a flat dict containing
{
'foo.0.bar': 'one',
'foo.0.wizz': '1',
'foo.1.bar': 'two',
'foo.1.wizz': '2'
}
will get turned into a dict with one element 'foo' whose
value is a list. The list elements will each in turn be
dicts.
{
'foo' => [
{ 'bar': 'one', 'wizz': '1' }
{ 'bar': 'two', 'wizz': '2' }
],
}
If the key is intended to contain a literal '.', then it must
be escaped as '..'. ie a flat dict
{
'foo..bar': 'wizz',
'bar.foo..bar': 'eek',
'bar.hello': 'world'
}
Will end up as
{
'foo.bar': 'wizz',
'bar': {
'foo.bar': 'eek',
'hello': 'world'
}
}
The intent of this function is that it allows a set of QemuOpts
to be turned into a nested data structure that mirrors the nested
used when the same object is defined over QMP.
Signed-off-by: Daniel P. Berrange <address@hidden>
---
include/qapi/qmp/qdict.h | 1 +
qobject/qdict.c | 237 +++++++++++++++++++++++++++++++++++++++++++++++
tests/check-qdict.c | 114 +++++++++++++++++++++++
3 files changed, 352 insertions(+)
diff --git a/include/qapi/qmp/qdict.h b/include/qapi/qmp/qdict.h
index 71b8eb0..8a3ac13 100644
--- a/include/qapi/qmp/qdict.h
+++ b/include/qapi/qmp/qdict.h
@@ -73,6 +73,7 @@ void qdict_flatten(QDict *qdict);
void qdict_extract_subqdict(QDict *src, QDict **dst, const char *start);
void qdict_array_split(QDict *src, QList **dst);
int qdict_array_entries(QDict *src, const char *subqdict);
+QObject *qdict_crumple(QDict *src, bool recursive, Error **errp);
void qdict_join(QDict *dest, QDict *src, bool overwrite);
diff --git a/qobject/qdict.c b/qobject/qdict.c
index 9833bd0..b0f3447 100644
--- a/qobject/qdict.c
+++ b/qobject/qdict.c
@@ -682,6 +682,243 @@ void qdict_array_split(QDict *src, QList **dst)
}
}
+
+/**
+ * qdict_split_flat_key:
+ *
+ * Given a flattened key such as 'foo.0.bar', split it
+ * into two parts at the first '.' separator. Allows
+ * double dot ('..') to escape the normal separator.
+ *
+ * eg
+ * 'foo.0.bar' -> prefix='foo' and suffix='0.bar'
+ * 'foo..0.bar' -> prefix='foo.0' and suffix='bar'
+ *
+ * The '..' sequence will be unescaped in the returned
+ * 'prefix' string. The 'suffix' string will be left
+ * in escaped format, so it can be fed back into the
+ * qdict_split_flat_key() key as the input later.
+ */
+static void qdict_split_flat_key(const char *key, char **prefix, char **suffix)
+{
+ const char *separator;
+ size_t i, j;
+
+ /* Find first '.' separator, but if there is a pair '..'
+ * that acts as an escape, so skip over '..' */
+ separator = NULL;
+ do {
+ if (separator) {
+ separator += 2;
+ } else {
+ separator = key;
+ }
+ separator = strchr(separator, '.');
+ } while (separator && *(separator + 1) == '.');
+
+ if (separator) {
+ *prefix = g_strndup(key,
+ separator - key);
+ *suffix = g_strdup(separator + 1);
+ } else {
+ *prefix = g_strdup(key);
+ *suffix = NULL;
+ }
+
+ /* Unescape the '..' sequence into '.' */
+ for (i = 0, j = 0; (*prefix)[i] != '\0'; i++, j++) {
+ if ((*prefix)[i] == '.' &&
+ (*prefix)[i + 1] == '.') {
+ i++;
+ }
+ (*prefix)[j] = (*prefix)[i];
+ }
+ (*prefix)[j] = '\0';
+}
+
+
+/**
+ * qdict_crumple:
+ *
+ * Reverses the flattening done by qdict_flatten by
+ * crumpling the dicts into a nested structure. Similar
+ * qdict_array_split, but copes with arbitrary nesting
+ * of dicts & arrays, not meely one level of arrays
+ *
+ * { 'foo.0.bar': 'one', 'foo.0.wizz': '1',
+ * 'foo.1.bar': 'two', 'foo.1.wizz': '2' }
+ *
+ * =>
+ *
+ * {
+ * 'foo' => [
+ * { 'bar': 'one', 'wizz': '1' }
+ * { 'bar': 'two', 'wizz': '2' }
+ * ],
+ * }
+ *
+ */
+QObject *qdict_crumple(QDict *src, bool recursive, Error **errp)
+{
+ const QDictEntry *entry, *next;
+ QDict *two_level, *multi_level = NULL;
+ QObject *dst = NULL, *child;
+ bool isList = false;
+ ssize_t list_max = -1;
+ size_t list_len = 0;
+ size_t i;
+ int64_t val;
+ char *prefix, *suffix;
+
+ two_level = qdict_new();
+ entry = qdict_first(src);
+
+ /* Step 1: split our totally flat dict into a two level dict */
+ while (entry != NULL) {
+ next = qdict_next(src, entry);
+
+ if (qobject_type(entry->value) == QTYPE_QDICT ||
+ qobject_type(entry->value) == QTYPE_QLIST) {
+ error_setg(errp, "Value %s is not a scalar",
+ entry->key);
+ goto error;
+ }
+
+ qdict_split_flat_key(entry->key, &prefix, &suffix);
+
+ child = qdict_get(two_level, prefix);
+ if (suffix) {
+ if (child) {
+ if (qobject_type(child) != QTYPE_QDICT) {
+ error_setg(errp, "Key %s prefix is already set as a
scalar",
+ prefix);
+ goto error;
+ }
+ } else {
+ child = (QObject *)qdict_new();
+ qdict_put_obj(two_level, prefix, child);
+ }
+ qobject_incref(entry->value);
+ qdict_put_obj(qobject_to_qdict(child), suffix, entry->value);
+ } else {
+ if (child) {
+ error_setg(errp, "Key %s prefix is already set as a dict",
+ prefix);
+ goto error;
+ }
+ qobject_incref(entry->value);
+ qdict_put_obj(two_level, prefix, entry->value);
+ }
+
+ g_free(suffix);
+ g_free(prefix);
+ suffix = prefix = NULL;
+
+ entry = next;
+ }
+
+ /* Step 2: optionally process the two level dict recursively
+ * into a multi-level dict */
+ if (recursive) {
+ multi_level = qdict_new();
+ entry = qdict_first(two_level);
+ while (entry != NULL) {
+ next = qdict_next(two_level, entry);
+
+ if (qobject_type(entry->value) == QTYPE_QDICT) {
+ child = qdict_crumple(qobject_to_qdict(entry->value),
+ recursive, errp);
+ if (!child) {
+ goto error;
+ }
+
+ qdict_put_obj(multi_level, entry->key, child);
+ } else {
+ qobject_incref(entry->value);
+ qdict_put_obj(multi_level, entry->key, entry->value);
+ }
+
+ entry = next;
+ }
+ QDECREF(two_level);
+ } else {
+ multi_level = two_level;
+ }
+ two_level = NULL;
+
+ /* Step 3: detect if we need to turn our dict into list */
+ entry = qdict_first(multi_level);
+ while (entry != NULL) {
+ next = qdict_next(multi_level, entry);
+
+ errno = 0;
+ if (qemu_strtoll(entry->key, NULL, 10, &val) == 0) {
+ if (!dst) {
+ dst = (QObject *)qlist_new();
+ isList = true;
+ } else if (!isList) {
+ error_setg(errp,
+ "Key '%s' is for a list, but previous key is "
+ "for a dict", entry->key);
+ goto error;
+ }
+ list_len++;
+ if (val > list_max) {
+ list_max = val;
+ }
+ } else {
+ if (!dst) {
+ dst = (QObject *)multi_level;
+ qobject_incref(dst);
+ isList = false;
+ } else if (isList) {
+ error_setg(errp,
+ "Key '%s' is for a dict, but previous key is "
+ "for a list", entry->key);
+ goto error;
+ }
+ }
+
+ entry = next;
+ }
+
+ /* Step 4: Turn the dict into a list */
+ if (isList) {
+ if (list_len != (list_max + 1)) {
+ error_setg(errp, "List indexes are not continuous, "
+ "saw %zu elements but %zu largest index",
+ list_len, list_max);
+ goto error;
+ }
+
+ for (i = 0; i < list_len; i++) {
+ char *key = g_strdup_printf("%zu", i);
+
+ child = qdict_get(multi_level, key);
+ g_free(key);
+ if (!child) {
+ error_setg(errp, "Unexpected missing list entry %zu", i);
+ goto error;
+ }
+
+ qobject_incref(child);
+ qlist_append_obj((QList *)dst, child);
+ }
+ }
+ QDECREF(multi_level);
+
+ return dst;
+
+ error:
+ g_free(suffix);
+ g_free(prefix);
+ QDECREF(multi_level);
+ QDECREF(two_level);
+ qobject_decref(dst);
+ return NULL;
+}
+
+
/**
* qdict_array_entries(): Returns the number of direct array entries if the
* sub-QDict of src specified by the prefix in subqdict (or src itself for
diff --git a/tests/check-qdict.c b/tests/check-qdict.c
index a43056c..20aa1af 100644
--- a/tests/check-qdict.c
+++ b/tests/check-qdict.c
@@ -596,6 +596,113 @@ static void qdict_join_test(void)
QDECREF(dict2);
}
+
+static void qdict_crumple_test_nonrecursive(void)
+{
+ QDict *src, *dst, *rules;
+ QObject *child;
+
+ src = qdict_new();
+ qdict_put(src, "rule.0.match", qstring_from_str("fred"));
+ qdict_put(src, "rule.0.policy", qstring_from_str("allow"));
+ qdict_put(src, "rule.1.match", qstring_from_str("bob"));
+ qdict_put(src, "rule.1.policy", qstring_from_str("deny"));
+
+ dst = (QDict *)qdict_crumple(src, false, &error_abort);
+
+ g_assert_cmpint(qdict_size(dst), ==, 1);
+
+ child = qdict_get(dst, "rule");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QDICT);
+
+ rules = qdict_get_qdict(dst, "rule");
+
+ g_assert_cmpstr("fred", ==, qdict_get_str(rules, "0.match"));
+ g_assert_cmpstr("allow", ==, qdict_get_str(rules, "0.policy"));
+ g_assert_cmpstr("bob", ==, qdict_get_str(rules, "1.match"));
+ g_assert_cmpstr("deny", ==, qdict_get_str(rules, "1.policy"));
+
+ QDECREF(src);
+ QDECREF(dst);
+}
+
+
+static void qdict_crumple_test_recursive(void)
+{
+ QDict *src, *dst, *rule;
+ QObject *child;
+ QList *rules;
+
+ src = qdict_new();
+ qdict_put(src, "rule.0.match", qstring_from_str("fred"));
+ qdict_put(src, "rule.0.policy", qstring_from_str("allow"));
+ qdict_put(src, "rule.1.match", qstring_from_str("bob"));
+ qdict_put(src, "rule.1.policy", qstring_from_str("deny"));
+
+ dst = (QDict *)qdict_crumple(src, true, &error_abort);
+
+ g_assert_cmpint(qdict_size(dst), ==, 1);
+
+ child = qdict_get(dst, "rule");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QLIST);
+
+ rules = qdict_get_qlist(dst, "rule");
+ g_assert_cmpint(qlist_size(rules), ==, 2);
+
+ rule = qobject_to_qdict(qlist_pop(rules));
+ g_assert_cmpstr("fred", ==, qdict_get_str(rule, "match"));
+ g_assert_cmpstr("allow", ==, qdict_get_str(rule, "policy"));
+ QDECREF(rule);
+
+ rule = qobject_to_qdict(qlist_pop(rules));
+ g_assert_cmpstr("bob", ==, qdict_get_str(rule, "match"));
+ g_assert_cmpstr("deny", ==, qdict_get_str(rule, "policy"));
+ QDECREF(rule);
+
+ QDECREF(src);
+ QDECREF(dst);
+}
+
+
+static void qdict_crumple_test_bad_inputs(void)
+{
+ QDict *src;
+ Error *error = NULL;
+
+ src = qdict_new();
+ /* rule.0 can't be both a string and a dict */
+ qdict_put(src, "rule.0", qstring_from_str("fred"));
+ qdict_put(src, "rule.0.policy", qstring_from_str("allow"));
+
+ g_assert(qdict_crumple(src, true, &error) == NULL);
+ g_assert(error != NULL);
+ error_free(error);
+ error = NULL;
+ QDECREF(src);
+
+ src = qdict_new();
+ /* rule can't be both a list and a dict */
+ qdict_put(src, "rule.0", qstring_from_str("fred"));
+ qdict_put(src, "rule.a", qstring_from_str("allow"));
+
+ g_assert(qdict_crumple(src, true, &error) == NULL);
+ g_assert(error != NULL);
+ error_free(error);
+ error = NULL;
+ QDECREF(src);
+
+ src = qdict_new();
+ /* The input should be flat, ie no dicts or lists */
+ qdict_put(src, "rule.0", qdict_new());
+ qdict_put(src, "rule.a", qstring_from_str("allow"));
+
+ g_assert(qdict_crumple(src, true, &error) == NULL);
+ g_assert(error != NULL);
+ error_free(error);
+ error = NULL;
+ QDECREF(src);
+}
+
/*
* Errors test-cases
*/
@@ -743,6 +850,13 @@ int main(int argc, char **argv)
g_test_add_func("/errors/put_exists", qdict_put_exists_test);
g_test_add_func("/errors/get_not_exists", qdict_get_not_exists_test);
+ g_test_add_func("/public/crumple/nonrecursive",
+ qdict_crumple_test_nonrecursive);
+ g_test_add_func("/public/crumple/recursive",
+ qdict_crumple_test_recursive);
+ g_test_add_func("/public/crumple/bad_inputs",
+ qdict_crumple_test_bad_inputs);
+
/* The Big one */
if (g_test_slow()) {
g_test_add_func("/stress/test", qdict_stress_test);
--
2.5.0
- [Qemu-devel] [PATCH v2 00/10] Provide a QOM-based authorization API, Daniel P. Berrange, 2016/03/07
- [Qemu-devel] [PATCH v2 01/10] qdict: implement a qdict_crumple method for un-flattening a dict,
Daniel P. Berrange <=
- [Qemu-devel] [PATCH v2 03/10] qom: support arbitrary non-scalar properties with -object, Daniel P. Berrange, 2016/03/07
- [Qemu-devel] [PATCH v2 04/10] util: add QAuthZ object as an authorization base class, Daniel P. Berrange, 2016/03/07
- [Qemu-devel] [PATCH v2 02/10] qapi: allow QmpInputVisitor to auto-cast types, Daniel P. Berrange, 2016/03/07
- [Qemu-devel] [PATCH v2 05/10] util: add QAuthZSimple object type for a simple access control list, Daniel P. Berrange, 2016/03/07
- [Qemu-devel] [PATCH v2 06/10] acl: delete existing ACL implementation, Daniel P. Berrange, 2016/03/07
- [Qemu-devel] [PATCH v2 07/10] qemu-nbd: add support for ACLs for TLS clients, Daniel P. Berrange, 2016/03/07
- [Qemu-devel] [PATCH v2 08/10] nbd: allow an ACL to be set with nbd-server-start QMP command, Daniel P. Berrange, 2016/03/07