From 603476c25c4d588a557ec2139352028f3157cba4 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Fri, 30 Sep 2016 15:45:25 +0100 Subject: [PATCH] qdict: implement a qdict_crumple method for un-flattening a dict MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Kevin Wolf Reviewed-by: Marc-André Lureau Signed-off-by: Daniel P. Berrange Message-Id: <1475246744-29302-3-git-send-email-berrange@redhat.com> Reviewed-by: Markus Armbruster [Parameter recursive dropped along with its tests; whitespace style touched up] Signed-off-by: Markus Armbruster --- include/qapi/qmp/qdict.h | 1 + qobject/qdict.c | 277 +++++++++++++++++++++++++++++++++++++++++++++++ tests/check-qdict.c | 158 +++++++++++++++++++++++++-- 3 files changed, 428 insertions(+), 8 deletions(-) diff --git a/include/qapi/qmp/qdict.h b/include/qapi/qmp/qdict.h index 71b8eb0416..fe9a4c5c60 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, Error **errp); void qdict_join(QDict *dest, QDict *src, bool overwrite); diff --git a/qobject/qdict.c b/qobject/qdict.c index 60f158c3b7..197b0fbd47 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" @@ -684,6 +685,282 @@ 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 + * + * Takes a flat dictionary whose keys use '.' separator to indicate + * nesting, and values are scalars, and crumples it into a nested + * structure. + * + * 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, 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 */ + 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), 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); + 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 * prefix == "") is valid as an array, i.e. the length of the created list if diff --git a/tests/check-qdict.c b/tests/check-qdict.c index 42da1e65a5..07b1c798d8 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" /* @@ -412,7 +413,6 @@ static void qdict_array_split_test(void) QDECREF(test_dict); - /* * Test the split of * @@ -518,7 +518,6 @@ static void qdict_join_test(void) dict1 = qdict_new(); dict2 = qdict_new(); - /* Test everything once without overwrite and once with */ do { @@ -528,7 +527,6 @@ static void qdict_join_test(void) g_assert(qdict_size(dict1) == 0); g_assert(qdict_size(dict2) == 0); - /* First iteration: Test movement */ /* Second iteration: Test empty source and non-empty destination */ qdict_put(dict2, "foo", qint_from_int(42)); @@ -542,7 +540,6 @@ static void qdict_join_test(void) g_assert(qdict_get_int(dict1, "foo") == 42); } - /* Test non-empty source and destination without conflict */ qdict_put(dict2, "bar", qint_from_int(23)); @@ -554,7 +551,6 @@ static void qdict_join_test(void) g_assert(qdict_get_int(dict1, "foo") == 42); g_assert(qdict_get_int(dict1, "bar") == 23); - /* Test conflict */ qdict_put(dict2, "foo", qint_from_int(84)); @@ -570,7 +566,6 @@ static void qdict_join_test(void) g_assert(qdict_get_int(dict2, "foo") == 84); } - /* Check the references */ g_assert(qdict_get(dict1, "foo")->refcnt == 1); g_assert(qdict_get(dict1, "bar")->refcnt == 1); @@ -579,7 +574,6 @@ static void qdict_join_test(void) g_assert(qdict_get(dict2, "foo")->refcnt == 1); } - /* Clean up */ qdict_del(dict1, "foo"); qdict_del(dict1, "bar"); @@ -590,11 +584,152 @@ static void qdict_join_test(void) } while (overwrite ^= true); - QDECREF(dict1); QDECREF(dict2); } +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, &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, &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, &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, &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, &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, &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, &error) == NULL); + g_assert(error != NULL); + error_free(error); + error = NULL; + QDECREF(src); +} + /* * Errors test-cases */ @@ -742,6 +877,13 @@ 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/recursive", + qdict_crumple_test_recursive); + 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); -- 2.11.4.GIT