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 nesting
used when the same object is defined over QMP.
Reviewed-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Kevin Wolf <kw...@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
---
include/qapi/qmp/qdict.h | 1 +
qobject/qdict.c | 289 +++++++++++++++++++++++++++++++++++++++++++++++
tests/check-qdict.c | 261 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 551 insertions(+)
diff --git a/include/qapi/qmp/qdict.h b/include/qapi/qmp/qdict.h
index 71b8eb0..e0d24e1 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(const 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 60f158c..c38e90e 100644
--- a/qobject/qdict.c
+++ b/qobject/qdict.c
@@ -17,6 +17,7 @@
#include "qapi/qmp/qbool.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qmp/qobject.h"
+#include "qapi/error.h"
#include "qemu/queue.h"
#include "qemu-common.h"
#include "qemu/cutils.h"
@@ -683,6 +684,294 @@ void qdict_array_split(QDict *src, QList **dst)
}
}
+
+/**
+ * qdict_split_flat_key:
+ * @key: the key string to split
+ * @prefix: non-NULL pointer to hold extracted prefix
+ * @suffix: non-NULL pointer to remaining suffix
+ *
+ * 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.
+ *
+ * e.g.
+ * '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.
+ *
+ * The caller is responsible for freeing the string returned in @prefix
+ * using g_free().
+ */
+static void qdict_split_flat_key(const char *key, char **prefix,
+ const 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 = 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] == '.') {
+ assert((*prefix)[i + 1] == '.');
+ i++;
+ }
+ (*prefix)[j] = (*prefix)[i];
+ }
+ (*prefix)[j] = '\0';
+}
+
+
+/**
+ * qdict_is_list:
+ * @maybe_list: dict to check if keys represent list elements.
+ *
+ * Determine whether all keys in @maybe_list are valid list elements.
+ * If @maybe_list is non-zero in length and all the keys look like
+ * valid list indexes, this will return 1. If @maybe_list is zero
+ * length or all keys are non-numeric then it will return 0 to indicate
+ * it is a normal qdict. If there is a mix of numeric and non-numeric
+ * keys, or the list indexes are non-contiguous, an error is reported.
+ *
+ * Returns: 1 if a valid list, 0 if a dict, -1 on error
+ */
+static int qdict_is_list(QDict *maybe_list, Error **errp)
+{
+ const QDictEntry *ent;
+ ssize_t len = 0;
+ ssize_t max = -1;
+ int is_list = -1;
+ int64_t val;
+
+ for (ent = qdict_first(maybe_list); ent != NULL;
+ ent = qdict_next(maybe_list, ent)) {
+
+ if (qemu_strtoll(ent->key, NULL, 10, &val) == 0) {
+ if (is_list == -1) {
+ is_list = 1;
+ } else if (!is_list) {
+ error_setg(errp,
+ "Cannot mix list and non-list keys");
+ return -1;
+ }
+ len++;
+ if (val > max) {
+ max = val;
+ }
+ } else {
+ if (is_list == -1) {
+ is_list = 0;
+ } else if (is_list) {
+ error_setg(errp,
+ "Cannot mix list and non-list keys");
+ return -1;
+ }
+ }
+ }
+
+ if (is_list == -1) {
+ assert(!qdict_size(maybe_list));
+ is_list = 0;
+ }
+
+ /* NB this isn't a perfect check - e.g. it won't catch
+ * a list containing '1', '+1', '01', '3', but that
+ * does not matter - we've still proved that the
+ * input is a list. It is up the caller to do a
+ * stricter check if desired */
+ if (len != (max + 1)) {
+ error_setg(errp, "List indices are not contiguous, "
+ "saw %zd elements but %zd largest index",
+ len, max);
+ return -1;
+ }
+
+ return is_list;
+}
+
+/**
+ * qdict_crumple:
+ * @src: the original flat dictionary (only scalar values) to crumple
+ * @recursive: true to recursively crumple nested dictionaries
+ *
+ * Takes a flat dictionary whose keys use '.' separator to indicate
+ * nesting, and values are scalars, and crumples it into a nested
+ * structure. If the @recursive parameter is false, then only the
+ * first level of structure implied by the keys will be crumpled. If
+ * @recursive is true, then the input will be recursively crumpled to
+ * expand all levels of structure in the keys.
+ *
+ * To include a literal '.' in a key name, it must be escaped as '..'
+ *
+ * For example, an input of:
+ *
+ * { 'foo.0.bar': 'one', 'foo.0.wizz': '1',
+ * 'foo.1.bar': 'two', 'foo.1.wizz': '2' }
+ *
+ * will result in an output of:
+ *
+ * {
+ * 'foo': [
+ * { 'bar': 'one', 'wizz': '1' },
+ * { 'bar': 'two', 'wizz': '2' }
+ * ],
+ * }
+ *
+ * The following scenarios in the input dict will result in an
+ * error being returned:
+ *
+ * - Any values in @src are non-scalar types
+ * - If keys in @src imply that a particular level is both a
+ * list and a dict. e.g., "foo.0.bar" and "foo.eek.bar".
+ * - If keys in @src imply that a particular level is a list,
+ * but the indices are non-contiguous. e.g. "foo.0.bar" and
+ * "foo.2.bar" without any "foo.1.bar" present.
+ * - If keys in @src represent list indexes, but are not in
+ * the "%zu" format. e.g. "foo.+0.bar"
+ *
+ * Returns: either a QDict or QList for the nested data structure, or NULL
+ * on error
+ */
+QObject *qdict_crumple(const QDict *src, bool recursive, Error **errp)
+{
+ const QDictEntry *ent;
+ QDict *two_level, *multi_level = NULL;
+ QObject *dst = NULL, *child;
+ size_t i;
+ char *prefix = NULL;
+ const char *suffix = NULL;
+ int is_list;
+
+ two_level = qdict_new();
+
+ /* Step 1: split our totally flat dict into a two level dict */
+ for (ent = qdict_first(src); ent != NULL; ent = qdict_next(src, ent)) {
+ if (qobject_type(ent->value) == QTYPE_QDICT ||
+ qobject_type(ent->value) == QTYPE_QLIST) {
+ error_setg(errp, "Value %s is not a scalar",
+ ent->key);
+ goto error;
+ }
+
+ qdict_split_flat_key(ent->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(ent->value);
+ qdict_put_obj(qobject_to_qdict(child), suffix, ent->value);
+ } else {
+ if (child) {
+ error_setg(errp, "Key %s prefix is already set as a dict",
+ prefix);
+ goto error;
+ }
+ qobject_incref(ent->value);
+ qdict_put_obj(two_level, prefix, ent->value);
+ }
+
+ g_free(prefix);
+ prefix = NULL;
+ }
+
+ /* Step 2: optionally process the two level dict recursively
+ * into a multi-level dict */
+ if (recursive) {
+ multi_level = qdict_new();
+ for (ent = qdict_first(two_level); ent != NULL;
+ ent = qdict_next(two_level, ent)) {
+
+ if (qobject_type(ent->value) == QTYPE_QDICT) {
+ child = qdict_crumple(qobject_to_qdict(ent->value),
+ recursive, errp);
+ if (!child) {
+ goto error;
+ }
+
+ qdict_put_obj(multi_level, ent->key, child);
+ } else {
+ qobject_incref(ent->value);
+ qdict_put_obj(multi_level, ent->key, ent->value);
+ }
+ }
+ QDECREF(two_level);
+ } else {
+ multi_level = two_level;
+ }
+ two_level = NULL;
+
+ /* Step 3: detect if we need to turn our dict into list */
+ is_list = qdict_is_list(multi_level, errp);
+ if (is_list < 0) {
+ goto error;
+ }
+
+ if (is_list) {
+ dst = QOBJECT(qlist_new());
+
+ for (i = 0; i < qdict_size(multi_level); i++) {
+ char *key = g_strdup_printf("%zu", i);
+
+ child = qdict_get(multi_level, key);
+ g_free(key);
+
+ if (!child) {
+ error_setg(errp, "Missing list index %zu", i);
+ goto error;
+ }
+
+ qobject_incref(child);
+ qlist_append_obj(qobject_to_qlist(dst), child);
+ }
+ QDECREF(multi_level);
+ multi_level = NULL;
+ } else {
+ dst = QOBJECT(multi_level);
+ }
+
+ return dst;
+
+ error:
+ 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 42da1e6..64c33ab 100644
--- a/tests/check-qdict.c
+++ b/tests/check-qdict.c
@@ -14,6 +14,7 @@
#include "qapi/qmp/qint.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
+#include "qapi/error.h"
#include "qemu-common.h"
/*
@@ -595,6 +596,255 @@ static void qdict_join_test(void)
QDECREF(dict2);
}
+
+static void qdict_crumple_test_nonrecursive(void)
+{
+ QDict *src, *dst, *rules, *vnc, *acl;
+ QObject *child, *res;
+
+ src = qdict_new();
+ qdict_put(src, "vnc.listen.addr", qstring_from_str("127.0.0.1"));
+ qdict_put(src, "vnc.listen.port", qstring_from_str("5901"));
+ 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"));
+ qdict_put(src, "acl..name", qstring_from_str("acl0"));
+ qdict_put(src, "acl.rule..name", qstring_from_str("acl0"));
+
+ res = qdict_crumple(src, false, &error_abort);
+
+ g_assert_cmpint(qobject_type(res), ==, QTYPE_QDICT);
+
+ dst = qobject_to_qdict(res);
+
+ g_assert_cmpint(qdict_size(dst), ==, 4);
+
+ child = qdict_get(dst, "vnc");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QDICT);
+ vnc = qdict_get_qdict(dst, "vnc");
+
+ g_assert_cmpint(qdict_size(vnc), ==, 2);
+
+ g_assert_cmpstr("127.0.0.1", ==, qdict_get_str(vnc, "listen.addr"));
+ g_assert_cmpstr("5901", ==, qdict_get_str(vnc, "listen.port"));
+
+ child = qdict_get(dst, "rule");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QDICT);
+ rules = qdict_get_qdict(dst, "rule");
+
+ g_assert_cmpint(qdict_size(rules), ==, 4);
+
+ 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"));
+
+ /* With non-recursive crumpling, we should only see the first
+ * level names unescaped */
+ g_assert_cmpstr("acl0", ==, qdict_get_str(dst, "acl.name"));
+ child = qdict_get(dst, "acl");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QDICT);
+ acl = qdict_get_qdict(dst, "acl");
+ g_assert_cmpstr("acl0", ==, qdict_get_str(acl, "rule..name"));
+
+ QDECREF(src);
+ QDECREF(dst);
+}
+
+
+static void qdict_crumple_test_listtop(void)
+{
+ QDict *src, *rule;
+ QList *rules;
+ QObject *res;
+
+ src = qdict_new();
+ qdict_put(src, "0.match.name", qstring_from_str("Fred"));
+ qdict_put(src, "0.match.email", qstring_from_str("f...@example.com"));
+ qdict_put(src, "0.policy", qstring_from_str("allow"));
+ qdict_put(src, "1.match.name", qstring_from_str("Bob"));
+ qdict_put(src, "1.match.email", qstring_from_str("b...@example.com"));
+ qdict_put(src, "1.policy", qstring_from_str("deny"));
+
+ res = qdict_crumple(src, false, &error_abort);
+
+ g_assert_cmpint(qobject_type(res), ==, QTYPE_QLIST);
+
+ rules = qobject_to_qlist(res);
+
+ g_assert_cmpint(qlist_size(rules), ==, 2);
+
+ g_assert_cmpint(qobject_type(qlist_peek(rules)), ==, QTYPE_QDICT);
+ rule = qobject_to_qdict(qlist_pop(rules));
+ g_assert_cmpint(qdict_size(rule), ==, 3);
+
+ g_assert_cmpstr("Fred", ==, qdict_get_str(rule, "match.name"));
+ g_assert_cmpstr("f...@example.com", ==, qdict_get_str(rule,
"match.email"));
+ g_assert_cmpstr("allow", ==, qdict_get_str(rule, "policy"));
+ QDECREF(rule);
+
+ g_assert_cmpint(qobject_type(qlist_peek(rules)), ==, QTYPE_QDICT);
+ rule = qobject_to_qdict(qlist_pop(rules));
+ g_assert_cmpint(qdict_size(rule), ==, 3);
+
+ g_assert_cmpstr("Bob", ==, qdict_get_str(rule, "match.name"));
+ g_assert_cmpstr("b...@example.com", ==, qdict_get_str(rule,
"match.email"));
+ g_assert_cmpstr("deny", ==, qdict_get_str(rule, "policy"));
+ QDECREF(rule);
+
+ QDECREF(src);
+ qobject_decref(res);
+}
+
+
+static void qdict_crumple_test_recursive(void)
+{
+ QDict *src, *dst, *rule, *vnc, *acl, *listen;
+ QObject *child, *res;
+ QList *rules;
+
+ src = qdict_new();
+ qdict_put(src, "vnc.listen.addr", qstring_from_str("127.0.0.1"));
+ qdict_put(src, "vnc.listen.port", qstring_from_str("5901"));
+ qdict_put(src, "vnc.acl.rules.0.match", qstring_from_str("fred"));
+ qdict_put(src, "vnc.acl.rules.0.policy", qstring_from_str("allow"));
+ qdict_put(src, "vnc.acl.rules.1.match", qstring_from_str("bob"));
+ qdict_put(src, "vnc.acl.rules.1.policy", qstring_from_str("deny"));
+ qdict_put(src, "vnc.acl.default", qstring_from_str("deny"));
+ qdict_put(src, "vnc.acl..name", qstring_from_str("acl0"));
+ qdict_put(src, "vnc.acl.rule..name", qstring_from_str("acl0"));
+
+ res = qdict_crumple(src, true, &error_abort);
+
+ g_assert_cmpint(qobject_type(res), ==, QTYPE_QDICT);
+
+ dst = qobject_to_qdict(res);
+
+ g_assert_cmpint(qdict_size(dst), ==, 1);
+
+ child = qdict_get(dst, "vnc");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QDICT);
+ vnc = qobject_to_qdict(child);
+
+ child = qdict_get(vnc, "listen");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QDICT);
+ listen = qobject_to_qdict(child);
+ g_assert_cmpstr("127.0.0.1", ==, qdict_get_str(listen, "addr"));
+ g_assert_cmpstr("5901", ==, qdict_get_str(listen, "port"));
+
+ child = qdict_get(vnc, "acl");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QDICT);
+ acl = qobject_to_qdict(child);
+
+ child = qdict_get(acl, "rules");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QLIST);
+ rules = qobject_to_qlist(child);
+ g_assert_cmpint(qlist_size(rules), ==, 2);
+
+ rule = qobject_to_qdict(qlist_pop(rules));
+ g_assert_cmpint(qdict_size(rule), ==, 2);
+ 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_cmpint(qdict_size(rule), ==, 2);
+ g_assert_cmpstr("bob", ==, qdict_get_str(rule, "match"));
+ g_assert_cmpstr("deny", ==, qdict_get_str(rule, "policy"));
+ QDECREF(rule);
+
+ /* With recursive crumpling, we should see all names unescaped */
+ g_assert_cmpstr("acl0", ==, qdict_get_str(vnc, "acl.name"));
+ child = qdict_get(vnc, "acl");
+ g_assert_cmpint(qobject_type(child), ==, QTYPE_QDICT);
+ acl = qdict_get_qdict(vnc, "acl");
+ g_assert_cmpstr("acl0", ==, qdict_get_str(acl, "rule.name"));
+
+ QDECREF(src);
+ QDECREF(dst);
+}
+
+
+static void qdict_crumple_test_empty(void)
+{
+ QDict *src, *dst;
+
+ src = qdict_new();
+
+ dst = (QDict *)qdict_crumple(src, true, &error_abort);
+
+ g_assert_cmpint(qdict_size(dst), ==, 0);
+
+ 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.a", qdict_new());
+ qdict_put(src, "rule.b", 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();
+ /* List indexes must not have gaps */
+ qdict_put(src, "rule.0", qstring_from_str("deny"));
+ qdict_put(src, "rule.3", 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();
+ /* List indexes must be in %zu format */
+ qdict_put(src, "rule.0", qstring_from_str("deny"));
+ qdict_put(src, "rule.+1", 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
*/
@@ -742,6 +992,17 @@ 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/listtop",
+ qdict_crumple_test_listtop);
+ g_test_add_func("/public/crumple/empty",
+ qdict_crumple_test_empty);
+ 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);
--
2.7.4
