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Re: [Qemu-devel] [PATCH 06/13] block: Add block-specific QDict header
|
From: |
Markus Armbruster |
|
Subject: |
Re: [Qemu-devel] [PATCH 06/13] block: Add block-specific QDict header |
|
Date: |
Wed, 06 Jun 2018 15:17:32 +0200 |
|
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) |
MAINTAINERS files include/block/qdict.h under "Block layer core". Let's
split qobject/qdict.c as well, so it's there, too. Obvious patch
appended. Feel free to squash it into yours without giving me credit
for it.
PS: I tried to move block-qdict.c to block/, but totally failed at
persuading Make to link it into all programs that need it. Oh well.
>From 4614533375729c84c0599e1fed44420b29a180a6 Mon Sep 17 00:00:00 2001
From: Markus Armbruster <address@hidden>
Date: Wed, 6 Jun 2018 15:11:54 +0200
Subject: [PATCH] qobject: Move block-specific qdict code to block-qdict.c
Signed-off-by: Markus Armbruster <address@hidden>
---
MAINTAINERS | 1 +
qobject/Makefile.objs | 1 +
qobject/block-qdict.c | 637 ++++++++++++++++++++++++++++++++++++++++++
qobject/qdict.c | 629 -----------------------------------------
4 files changed, 639 insertions(+), 629 deletions(-)
create mode 100644 qobject/block-qdict.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 41cd3736a9..9f9835e052 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1365,6 +1365,7 @@ F: qemu-img*
F: qemu-io*
F: tests/qemu-iotests/
F: util/qemu-progress.c
+F: qobject/block-qdict.c
T: git git://repo.or.cz/qemu/kevin.git block
Block I/O path
diff --git a/qobject/Makefile.objs b/qobject/Makefile.objs
index 002d25873a..7b12c9cacf 100644
--- a/qobject/Makefile.objs
+++ b/qobject/Makefile.objs
@@ -1,2 +1,3 @@
util-obj-y = qnull.o qnum.o qstring.o qdict.o qlist.o qbool.o qlit.o
util-obj-y += qjson.o qobject.o json-lexer.o json-streamer.o json-parser.o
+util-obj-y += block-qdict.o
diff --git a/qobject/block-qdict.c b/qobject/block-qdict.c
new file mode 100644
index 0000000000..01c453a8c0
--- /dev/null
+++ b/qobject/block-qdict.c
@@ -0,0 +1,637 @@
+/*
+ * Special QDict functions used by the block layer
+ *
+ * Copyright (c) 2013-2018 Red Hat, Inc.
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "block/qdict.h"
+#include "qapi/qmp/qlist.h"
+#include "qemu/cutils.h"
+#include "qapi/error.h"
+
+/**
+ * qdict_copy_default(): If no entry mapped by 'key' exists in 'dst' yet, the
+ * value of 'key' in 'src' is copied there (and the refcount increased
+ * accordingly).
+ */
+void qdict_copy_default(QDict *dst, QDict *src, const char *key)
+{
+ QObject *val;
+
+ if (qdict_haskey(dst, key)) {
+ return;
+ }
+
+ val = qdict_get(src, key);
+ if (val) {
+ qdict_put_obj(dst, key, qobject_ref(val));
+ }
+}
+
+/**
+ * qdict_set_default_str(): If no entry mapped by 'key' exists in 'dst' yet, a
+ * new QString initialised by 'val' is put there.
+ */
+void qdict_set_default_str(QDict *dst, const char *key, const char *val)
+{
+ if (qdict_haskey(dst, key)) {
+ return;
+ }
+
+ qdict_put_str(dst, key, val);
+}
+
+static void qdict_flatten_qdict(QDict *qdict, QDict *target,
+ const char *prefix);
+
+static void qdict_flatten_qlist(QList *qlist, QDict *target, const char
*prefix)
+{
+ QObject *value;
+ const QListEntry *entry;
+ char *new_key;
+ int i;
+
+ /* This function is never called with prefix == NULL, i.e., it is always
+ * called from within qdict_flatten_q(list|dict)(). Therefore, it does not
+ * need to remove list entries during the iteration (the whole list will be
+ * deleted eventually anyway from qdict_flatten_qdict()). */
+ assert(prefix);
+
+ entry = qlist_first(qlist);
+
+ for (i = 0; entry; entry = qlist_next(entry), i++) {
+ value = qlist_entry_obj(entry);
+ new_key = g_strdup_printf("%s.%i", prefix, i);
+
+ if (qobject_type(value) == QTYPE_QDICT) {
+ qdict_flatten_qdict(qobject_to(QDict, value), target, new_key);
+ } else if (qobject_type(value) == QTYPE_QLIST) {
+ qdict_flatten_qlist(qobject_to(QList, value), target, new_key);
+ } else {
+ /* All other types are moved to the target unchanged. */
+ qdict_put_obj(target, new_key, qobject_ref(value));
+ }
+
+ g_free(new_key);
+ }
+}
+
+static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char
*prefix)
+{
+ QObject *value;
+ const QDictEntry *entry, *next;
+ char *new_key;
+ bool delete;
+
+ entry = qdict_first(qdict);
+
+ while (entry != NULL) {
+
+ next = qdict_next(qdict, entry);
+ value = qdict_entry_value(entry);
+ new_key = NULL;
+ delete = false;
+
+ if (prefix) {
+ new_key = g_strdup_printf("%s.%s", prefix, entry->key);
+ }
+
+ if (qobject_type(value) == QTYPE_QDICT) {
+ /* Entries of QDicts are processed recursively, the QDict object
+ * itself disappears. */
+ qdict_flatten_qdict(qobject_to(QDict, value), target,
+ new_key ? new_key : entry->key);
+ delete = true;
+ } else if (qobject_type(value) == QTYPE_QLIST) {
+ qdict_flatten_qlist(qobject_to(QList, value), target,
+ new_key ? new_key : entry->key);
+ delete = true;
+ } else if (prefix) {
+ /* All other objects are moved to the target unchanged. */
+ qdict_put_obj(target, new_key, qobject_ref(value));
+ delete = true;
+ }
+
+ g_free(new_key);
+
+ if (delete) {
+ qdict_del(qdict, entry->key);
+
+ /* Restart loop after modifying the iterated QDict */
+ entry = qdict_first(qdict);
+ continue;
+ }
+
+ entry = next;
+ }
+}
+
+/**
+ * qdict_flatten(): For each nested QDict with key x, all fields with key y
+ * are moved to this QDict and their key is renamed to "x.y". For each nested
+ * QList with key x, the field at index y is moved to this QDict with the key
+ * "x.y" (i.e., the reverse of what qdict_array_split() does).
+ * This operation is applied recursively for nested QDicts and QLists.
+ */
+void qdict_flatten(QDict *qdict)
+{
+ qdict_flatten_qdict(qdict, qdict, NULL);
+}
+
+/* extract all the src QDict entries starting by start into dst */
+void qdict_extract_subqdict(QDict *src, QDict **dst, const char *start)
+
+{
+ const QDictEntry *entry, *next;
+ const char *p;
+
+ *dst = qdict_new();
+ entry = qdict_first(src);
+
+ while (entry != NULL) {
+ next = qdict_next(src, entry);
+ if (strstart(entry->key, start, &p)) {
+ qdict_put_obj(*dst, p, qobject_ref(entry->value));
+ qdict_del(src, entry->key);
+ }
+ entry = next;
+ }
+}
+
+static int qdict_count_prefixed_entries(const QDict *src, const char *start)
+{
+ const QDictEntry *entry;
+ int count = 0;
+
+ for (entry = qdict_first(src); entry; entry = qdict_next(src, entry)) {
+ if (strstart(entry->key, start, NULL)) {
+ if (count == INT_MAX) {
+ return -ERANGE;
+ }
+ count++;
+ }
+ }
+
+ return count;
+}
+
+/**
+ * qdict_array_split(): This function moves array-like elements of a QDict into
+ * a new QList. Every entry in the original QDict with a key "%u" or one
+ * prefixed "%u.", where %u designates an unsigned integer starting at 0 and
+ * incrementally counting up, will be moved to a new QDict at index %u in the
+ * output QList with the key prefix removed, if that prefix is "%u.". If the
+ * whole key is just "%u", the whole QObject will be moved unchanged without
+ * creating a new QDict. The function terminates when there is no entry in the
+ * QDict with a prefix directly (incrementally) following the last one; it also
+ * returns if there are both entries with "%u" and "%u." for the same index %u.
+ * Example: {"0.a": 42, "0.b": 23, "1.x": 0, "4.y": 1, "o.o": 7, "2": 66}
+ * (or {"1.x": 0, "4.y": 1, "0.a": 42, "o.o": 7, "0.b": 23, "2": 66})
+ * => [{"a": 42, "b": 23}, {"x": 0}, 66]
+ * and {"4.y": 1, "o.o": 7} (remainder of the old QDict)
+ */
+void qdict_array_split(QDict *src, QList **dst)
+{
+ unsigned i;
+
+ *dst = qlist_new();
+
+ for (i = 0; i < UINT_MAX; i++) {
+ QObject *subqobj;
+ bool is_subqdict;
+ QDict *subqdict;
+ char indexstr[32], prefix[32];
+ size_t snprintf_ret;
+
+ snprintf_ret = snprintf(indexstr, 32, "%u", i);
+ assert(snprintf_ret < 32);
+
+ subqobj = qdict_get(src, indexstr);
+
+ snprintf_ret = snprintf(prefix, 32, "%u.", i);
+ assert(snprintf_ret < 32);
+
+ /* Overflow is the same as positive non-zero results */
+ is_subqdict = qdict_count_prefixed_entries(src, prefix);
+
+ // There may be either a single subordinate object (named "%u") or
+ // multiple objects (each with a key prefixed "%u."), but not both.
+ if (!subqobj == !is_subqdict) {
+ break;
+ }
+
+ if (is_subqdict) {
+ qdict_extract_subqdict(src, &subqdict, prefix);
+ assert(qdict_size(subqdict) > 0);
+ } else {
+ qobject_ref(subqobj);
+ qdict_del(src, indexstr);
+ }
+
+ qlist_append_obj(*dst, subqobj ?: QOBJECT(subqdict));
+ }
+}
+
+/**
+ * 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_strtoi64(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) {
+ QDict *child_dict = qobject_to(QDict, child);
+ if (!child_dict) {
+ if (child) {
+ error_setg(errp, "Key %s prefix is already set as a
scalar",
+ prefix);
+ goto error;
+ }
+
+ child_dict = qdict_new();
+ qdict_put_obj(two_level, prefix, QOBJECT(child_dict));
+ }
+
+ qdict_put_obj(child_dict, suffix, qobject_ref(ent->value));
+ } else {
+ if (child) {
+ error_setg(errp, "Key %s prefix is already set as a dict",
+ prefix);
+ goto error;
+ }
+ qdict_put_obj(two_level, prefix, qobject_ref(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)) {
+ QDict *dict = qobject_to(QDict, ent->value);
+ if (dict) {
+ child = qdict_crumple(dict, errp);
+ if (!child) {
+ goto error;
+ }
+
+ qdict_put_obj(multi_level, ent->key, child);
+ } else {
+ qdict_put_obj(multi_level, ent->key, qobject_ref(ent->value));
+ }
+ }
+ qobject_unref(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;
+ }
+
+ qlist_append_obj(qobject_to(QList, dst), qobject_ref(child));
+ }
+ qobject_unref(multi_level);
+ multi_level = NULL;
+ } else {
+ dst = QOBJECT(multi_level);
+ }
+
+ return dst;
+
+ error:
+ g_free(prefix);
+ qobject_unref(multi_level);
+ qobject_unref(two_level);
+ qobject_unref(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
+ * the sub-QDict would become empty after calling qdict_array_split() on it. If
+ * the array is not valid, -EINVAL is returned.
+ */
+int qdict_array_entries(QDict *src, const char *subqdict)
+{
+ const QDictEntry *entry;
+ unsigned i;
+ unsigned entries = 0;
+ size_t subqdict_len = strlen(subqdict);
+
+ assert(!subqdict_len || subqdict[subqdict_len - 1] == '.');
+
+ /* qdict_array_split() loops until UINT_MAX, but as we want to return
+ * negative errors, we only have a signed return value here. Any additional
+ * entries will lead to -EINVAL. */
+ for (i = 0; i < INT_MAX; i++) {
+ QObject *subqobj;
+ int subqdict_entries;
+ char *prefix = g_strdup_printf("%s%u.", subqdict, i);
+
+ subqdict_entries = qdict_count_prefixed_entries(src, prefix);
+
+ /* Remove ending "." */
+ prefix[strlen(prefix) - 1] = 0;
+ subqobj = qdict_get(src, prefix);
+
+ g_free(prefix);
+
+ if (subqdict_entries < 0) {
+ return subqdict_entries;
+ }
+
+ /* There may be either a single subordinate object (named "%u") or
+ * multiple objects (each with a key prefixed "%u."), but not both. */
+ if (subqobj && subqdict_entries) {
+ return -EINVAL;
+ } else if (!subqobj && !subqdict_entries) {
+ break;
+ }
+
+ entries += subqdict_entries ? subqdict_entries : 1;
+ }
+
+ /* Consider everything handled that isn't part of the given sub-QDict */
+ for (entry = qdict_first(src); entry; entry = qdict_next(src, entry)) {
+ if (!strstart(qdict_entry_key(entry), subqdict, NULL)) {
+ entries++;
+ }
+ }
+
+ /* Anything left in the sub-QDict that wasn't handled? */
+ if (qdict_size(src) != entries) {
+ return -EINVAL;
+ }
+
+ return i;
+}
+
+/**
+ * qdict_join(): Absorb the src QDict into the dest QDict, that is, move all
+ * elements from src to dest.
+ *
+ * If an element from src has a key already present in dest, it will not be
+ * moved unless overwrite is true.
+ *
+ * If overwrite is true, the conflicting values in dest will be discarded and
+ * replaced by the corresponding values from src.
+ *
+ * Therefore, with overwrite being true, the src QDict will always be empty
when
+ * this function returns. If overwrite is false, the src QDict will be empty
+ * iff there were no conflicts.
+ */
+void qdict_join(QDict *dest, QDict *src, bool overwrite)
+{
+ const QDictEntry *entry, *next;
+
+ entry = qdict_first(src);
+ while (entry) {
+ next = qdict_next(src, entry);
+
+ if (overwrite || !qdict_haskey(dest, entry->key)) {
+ qdict_put_obj(dest, entry->key, qobject_ref(entry->value));
+ qdict_del(src, entry->key);
+ }
+
+ entry = next;
+ }
+}
+
+/**
+ * qdict_rename_keys(): Rename keys in qdict according to the replacements
+ * specified in the array renames. The array must be terminated by an entry
+ * with from = NULL.
+ *
+ * The renames are performed individually in the order of the array, so entries
+ * may be renamed multiple times and may or may not conflict depending on the
+ * order of the renames array.
+ *
+ * Returns true for success, false in error cases.
+ */
+bool qdict_rename_keys(QDict *qdict, const QDictRenames *renames, Error **errp)
+{
+ QObject *qobj;
+
+ while (renames->from) {
+ if (qdict_haskey(qdict, renames->from)) {
+ if (qdict_haskey(qdict, renames->to)) {
+ error_setg(errp, "'%s' and its alias '%s' can't be used at the
"
+ "same time", renames->to, renames->from);
+ return false;
+ }
+
+ qobj = qdict_get(qdict, renames->from);
+ qdict_put_obj(qdict, renames->to, qobject_ref(qobj));
+ qdict_del(qdict, renames->from);
+ }
+
+ renames++;
+ }
+ return true;
+}
diff --git a/qobject/qdict.c b/qobject/qdict.c
index 0554c64553..3d8c2f7bbc 100644
--- a/qobject/qdict.c
+++ b/qobject/qdict.c
@@ -11,17 +11,11 @@
*/
#include "qemu/osdep.h"
-#include "block/qdict.h"
#include "qapi/qmp/qnum.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qbool.h"
-#include "qapi/qmp/qlist.h"
#include "qapi/qmp/qnull.h"
#include "qapi/qmp/qstring.h"
-#include "qapi/error.h"
-#include "qemu/queue.h"
-#include "qemu-common.h"
-#include "qemu/cutils.h"
/**
* qdict_new(): Create a new QDict
@@ -464,626 +458,3 @@ void qdict_destroy_obj(QObject *obj)
g_free(qdict);
}
-
-/**
- * qdict_copy_default(): If no entry mapped by 'key' exists in 'dst' yet, the
- * value of 'key' in 'src' is copied there (and the refcount increased
- * accordingly).
- */
-void qdict_copy_default(QDict *dst, QDict *src, const char *key)
-{
- QObject *val;
-
- if (qdict_haskey(dst, key)) {
- return;
- }
-
- val = qdict_get(src, key);
- if (val) {
- qdict_put_obj(dst, key, qobject_ref(val));
- }
-}
-
-/**
- * qdict_set_default_str(): If no entry mapped by 'key' exists in 'dst' yet, a
- * new QString initialised by 'val' is put there.
- */
-void qdict_set_default_str(QDict *dst, const char *key, const char *val)
-{
- if (qdict_haskey(dst, key)) {
- return;
- }
-
- qdict_put_str(dst, key, val);
-}
-
-static void qdict_flatten_qdict(QDict *qdict, QDict *target,
- const char *prefix);
-
-static void qdict_flatten_qlist(QList *qlist, QDict *target, const char
*prefix)
-{
- QObject *value;
- const QListEntry *entry;
- char *new_key;
- int i;
-
- /* This function is never called with prefix == NULL, i.e., it is always
- * called from within qdict_flatten_q(list|dict)(). Therefore, it does not
- * need to remove list entries during the iteration (the whole list will be
- * deleted eventually anyway from qdict_flatten_qdict()). */
- assert(prefix);
-
- entry = qlist_first(qlist);
-
- for (i = 0; entry; entry = qlist_next(entry), i++) {
- value = qlist_entry_obj(entry);
- new_key = g_strdup_printf("%s.%i", prefix, i);
-
- if (qobject_type(value) == QTYPE_QDICT) {
- qdict_flatten_qdict(qobject_to(QDict, value), target, new_key);
- } else if (qobject_type(value) == QTYPE_QLIST) {
- qdict_flatten_qlist(qobject_to(QList, value), target, new_key);
- } else {
- /* All other types are moved to the target unchanged. */
- qdict_put_obj(target, new_key, qobject_ref(value));
- }
-
- g_free(new_key);
- }
-}
-
-static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char
*prefix)
-{
- QObject *value;
- const QDictEntry *entry, *next;
- char *new_key;
- bool delete;
-
- entry = qdict_first(qdict);
-
- while (entry != NULL) {
-
- next = qdict_next(qdict, entry);
- value = qdict_entry_value(entry);
- new_key = NULL;
- delete = false;
-
- if (prefix) {
- new_key = g_strdup_printf("%s.%s", prefix, entry->key);
- }
-
- if (qobject_type(value) == QTYPE_QDICT) {
- /* Entries of QDicts are processed recursively, the QDict object
- * itself disappears. */
- qdict_flatten_qdict(qobject_to(QDict, value), target,
- new_key ? new_key : entry->key);
- delete = true;
- } else if (qobject_type(value) == QTYPE_QLIST) {
- qdict_flatten_qlist(qobject_to(QList, value), target,
- new_key ? new_key : entry->key);
- delete = true;
- } else if (prefix) {
- /* All other objects are moved to the target unchanged. */
- qdict_put_obj(target, new_key, qobject_ref(value));
- delete = true;
- }
-
- g_free(new_key);
-
- if (delete) {
- qdict_del(qdict, entry->key);
-
- /* Restart loop after modifying the iterated QDict */
- entry = qdict_first(qdict);
- continue;
- }
-
- entry = next;
- }
-}
-
-/**
- * qdict_flatten(): For each nested QDict with key x, all fields with key y
- * are moved to this QDict and their key is renamed to "x.y". For each nested
- * QList with key x, the field at index y is moved to this QDict with the key
- * "x.y" (i.e., the reverse of what qdict_array_split() does).
- * This operation is applied recursively for nested QDicts and QLists.
- */
-void qdict_flatten(QDict *qdict)
-{
- qdict_flatten_qdict(qdict, qdict, NULL);
-}
-
-/* extract all the src QDict entries starting by start into dst */
-void qdict_extract_subqdict(QDict *src, QDict **dst, const char *start)
-
-{
- const QDictEntry *entry, *next;
- const char *p;
-
- *dst = qdict_new();
- entry = qdict_first(src);
-
- while (entry != NULL) {
- next = qdict_next(src, entry);
- if (strstart(entry->key, start, &p)) {
- qdict_put_obj(*dst, p, qobject_ref(entry->value));
- qdict_del(src, entry->key);
- }
- entry = next;
- }
-}
-
-static int qdict_count_prefixed_entries(const QDict *src, const char *start)
-{
- const QDictEntry *entry;
- int count = 0;
-
- for (entry = qdict_first(src); entry; entry = qdict_next(src, entry)) {
- if (strstart(entry->key, start, NULL)) {
- if (count == INT_MAX) {
- return -ERANGE;
- }
- count++;
- }
- }
-
- return count;
-}
-
-/**
- * qdict_array_split(): This function moves array-like elements of a QDict into
- * a new QList. Every entry in the original QDict with a key "%u" or one
- * prefixed "%u.", where %u designates an unsigned integer starting at 0 and
- * incrementally counting up, will be moved to a new QDict at index %u in the
- * output QList with the key prefix removed, if that prefix is "%u.". If the
- * whole key is just "%u", the whole QObject will be moved unchanged without
- * creating a new QDict. The function terminates when there is no entry in the
- * QDict with a prefix directly (incrementally) following the last one; it also
- * returns if there are both entries with "%u" and "%u." for the same index %u.
- * Example: {"0.a": 42, "0.b": 23, "1.x": 0, "4.y": 1, "o.o": 7, "2": 66}
- * (or {"1.x": 0, "4.y": 1, "0.a": 42, "o.o": 7, "0.b": 23, "2": 66})
- * => [{"a": 42, "b": 23}, {"x": 0}, 66]
- * and {"4.y": 1, "o.o": 7} (remainder of the old QDict)
- */
-void qdict_array_split(QDict *src, QList **dst)
-{
- unsigned i;
-
- *dst = qlist_new();
-
- for (i = 0; i < UINT_MAX; i++) {
- QObject *subqobj;
- bool is_subqdict;
- QDict *subqdict;
- char indexstr[32], prefix[32];
- size_t snprintf_ret;
-
- snprintf_ret = snprintf(indexstr, 32, "%u", i);
- assert(snprintf_ret < 32);
-
- subqobj = qdict_get(src, indexstr);
-
- snprintf_ret = snprintf(prefix, 32, "%u.", i);
- assert(snprintf_ret < 32);
-
- /* Overflow is the same as positive non-zero results */
- is_subqdict = qdict_count_prefixed_entries(src, prefix);
-
- // There may be either a single subordinate object (named "%u") or
- // multiple objects (each with a key prefixed "%u."), but not both.
- if (!subqobj == !is_subqdict) {
- break;
- }
-
- if (is_subqdict) {
- qdict_extract_subqdict(src, &subqdict, prefix);
- assert(qdict_size(subqdict) > 0);
- } else {
- qobject_ref(subqobj);
- qdict_del(src, indexstr);
- }
-
- qlist_append_obj(*dst, subqobj ?: QOBJECT(subqdict));
- }
-}
-
-/**
- * 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_strtoi64(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) {
- QDict *child_dict = qobject_to(QDict, child);
- if (!child_dict) {
- if (child) {
- error_setg(errp, "Key %s prefix is already set as a
scalar",
- prefix);
- goto error;
- }
-
- child_dict = qdict_new();
- qdict_put_obj(two_level, prefix, QOBJECT(child_dict));
- }
-
- qdict_put_obj(child_dict, suffix, qobject_ref(ent->value));
- } else {
- if (child) {
- error_setg(errp, "Key %s prefix is already set as a dict",
- prefix);
- goto error;
- }
- qdict_put_obj(two_level, prefix, qobject_ref(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)) {
- QDict *dict = qobject_to(QDict, ent->value);
- if (dict) {
- child = qdict_crumple(dict, errp);
- if (!child) {
- goto error;
- }
-
- qdict_put_obj(multi_level, ent->key, child);
- } else {
- qdict_put_obj(multi_level, ent->key, qobject_ref(ent->value));
- }
- }
- qobject_unref(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;
- }
-
- qlist_append_obj(qobject_to(QList, dst), qobject_ref(child));
- }
- qobject_unref(multi_level);
- multi_level = NULL;
- } else {
- dst = QOBJECT(multi_level);
- }
-
- return dst;
-
- error:
- g_free(prefix);
- qobject_unref(multi_level);
- qobject_unref(two_level);
- qobject_unref(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
- * the sub-QDict would become empty after calling qdict_array_split() on it. If
- * the array is not valid, -EINVAL is returned.
- */
-int qdict_array_entries(QDict *src, const char *subqdict)
-{
- const QDictEntry *entry;
- unsigned i;
- unsigned entries = 0;
- size_t subqdict_len = strlen(subqdict);
-
- assert(!subqdict_len || subqdict[subqdict_len - 1] == '.');
-
- /* qdict_array_split() loops until UINT_MAX, but as we want to return
- * negative errors, we only have a signed return value here. Any additional
- * entries will lead to -EINVAL. */
- for (i = 0; i < INT_MAX; i++) {
- QObject *subqobj;
- int subqdict_entries;
- char *prefix = g_strdup_printf("%s%u.", subqdict, i);
-
- subqdict_entries = qdict_count_prefixed_entries(src, prefix);
-
- /* Remove ending "." */
- prefix[strlen(prefix) - 1] = 0;
- subqobj = qdict_get(src, prefix);
-
- g_free(prefix);
-
- if (subqdict_entries < 0) {
- return subqdict_entries;
- }
-
- /* There may be either a single subordinate object (named "%u") or
- * multiple objects (each with a key prefixed "%u."), but not both. */
- if (subqobj && subqdict_entries) {
- return -EINVAL;
- } else if (!subqobj && !subqdict_entries) {
- break;
- }
-
- entries += subqdict_entries ? subqdict_entries : 1;
- }
-
- /* Consider everything handled that isn't part of the given sub-QDict */
- for (entry = qdict_first(src); entry; entry = qdict_next(src, entry)) {
- if (!strstart(qdict_entry_key(entry), subqdict, NULL)) {
- entries++;
- }
- }
-
- /* Anything left in the sub-QDict that wasn't handled? */
- if (qdict_size(src) != entries) {
- return -EINVAL;
- }
-
- return i;
-}
-
-/**
- * qdict_join(): Absorb the src QDict into the dest QDict, that is, move all
- * elements from src to dest.
- *
- * If an element from src has a key already present in dest, it will not be
- * moved unless overwrite is true.
- *
- * If overwrite is true, the conflicting values in dest will be discarded and
- * replaced by the corresponding values from src.
- *
- * Therefore, with overwrite being true, the src QDict will always be empty
when
- * this function returns. If overwrite is false, the src QDict will be empty
- * iff there were no conflicts.
- */
-void qdict_join(QDict *dest, QDict *src, bool overwrite)
-{
- const QDictEntry *entry, *next;
-
- entry = qdict_first(src);
- while (entry) {
- next = qdict_next(src, entry);
-
- if (overwrite || !qdict_haskey(dest, entry->key)) {
- qdict_put_obj(dest, entry->key, qobject_ref(entry->value));
- qdict_del(src, entry->key);
- }
-
- entry = next;
- }
-}
-
-/**
- * qdict_rename_keys(): Rename keys in qdict according to the replacements
- * specified in the array renames. The array must be terminated by an entry
- * with from = NULL.
- *
- * The renames are performed individually in the order of the array, so entries
- * may be renamed multiple times and may or may not conflict depending on the
- * order of the renames array.
- *
- * Returns true for success, false in error cases.
- */
-bool qdict_rename_keys(QDict *qdict, const QDictRenames *renames, Error **errp)
-{
- QObject *qobj;
-
- while (renames->from) {
- if (qdict_haskey(qdict, renames->from)) {
- if (qdict_haskey(qdict, renames->to)) {
- error_setg(errp, "'%s' and its alias '%s' can't be used at the
"
- "same time", renames->to, renames->from);
- return false;
- }
-
- qobj = qdict_get(qdict, renames->from);
- qdict_put_obj(qdict, renames->to, qobject_ref(qobj));
- qdict_del(qdict, renames->from);
- }
-
- renames++;
- }
- return true;
-}
--
2.17.1