diff mbox

[v3,01/10] qdict: implement a qdict_crumple method for un-flattening a dict

Message ID 1457636396-24983-1-git-send-email-berrange@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Daniel P. Berrangé March 10, 2016, 6:59 p.m. UTC
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 <berrange@redhat.com>
---
 include/qapi/qmp/qdict.h |   1 +
 qobject/qdict.c          | 267 +++++++++++++++++++++++++++++++++++++++++++++++
 tests/check-qdict.c      | 143 +++++++++++++++++++++++++
 3 files changed, 411 insertions(+)

Comments

Eric Blake March 21, 2016, 10:45 p.m. UTC | #1
On 03/10/2016 11:59 AM, Daniel P. Berrange wrote:
> 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.
> 

> 
> 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' => [

s/=>/:/

>      { 'bar': 'one', 'wizz': '1' }

s/$/,/

>      { 'bar': 'two', 'wizz': '2' }
>    ],
>  }
> 

> 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

s/the nested/the nesting/

> used when the same object is defined over QMP.
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  include/qapi/qmp/qdict.h |   1 +
>  qobject/qdict.c          | 267 +++++++++++++++++++++++++++++++++++++++++++++++
>  tests/check-qdict.c      | 143 +++++++++++++++++++++++++
>  3 files changed, 411 insertions(+)
> 
> +
> +/**
> + * 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.
> + */

Might be worth mentioning that prefix and suffix must both be non-NULL,
and that the caller must g_free() the two resulting strings.

> +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) == '.');

I'd probably have written separator[1] == '.', but your approach is
synonymous.

> +
> +    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] == '.') {

Technically, if (*prefix)[i] == '.', we could assert((*prefix)[i + 1] ==
'.'), since the only way to get a '.' in prefix is via escaping.  For
that matter, you could short-circuit (part of) the loop by doing a
strchr for '.' (if not found, the loop is not needed; if found, start
the reduction at that point rather on the bytes leading up to that point).

> +            i++;
> +        }
> +        (*prefix)[j] = (*prefix)[i];
> +    }
> +    (*prefix)[j] = '\0';
> +}
> +
> +
> +/**
> + * qdict_list_size:
> + * @maybe_List: dict that may be only list elements

s/List/list/

> + *
> + * Determine whether all keys in @maybe_list are
> + * valid list elements. They they are all valid,

s/They they/If they/

> + * then this returns the number of elements. If
> + * they all look like non-numeric keys, then returns
> + * zero. If there is a mix of numeric and non-numeric
> + * keys, then an error is set as it is both a list
> + * and a dict at once.
> + *
> + * Returns: number of list elemets, 0 if a dict, -1 on error

s/elemets/elements/

> + */
> +static ssize_t qdict_list_size(QDict *maybe_list, Error **errp)
> +{
> +    const QDictEntry *entry, *next;
> +    ssize_t len = 0;
> +    ssize_t max = -1;
> +    int is_list = -1;
> +    int64_t val;
> +
> +    entry = qdict_first(maybe_list);
> +    while (entry != NULL) {
> +        next = qdict_next(maybe_list, entry);
> +
> +        if (qemu_strtoll(entry->key, NULL, 10, &val) == 0) {
> +            if (is_list == -1) {
> +                is_list = 1;
> +            } else if (!is_list) {
> +                error_setg(errp,
> +                           "Key '%s' is for a list, but previous key is "
> +                           "for a dict", entry->key);

Keys are unsorted, so it's a bit hard to call it "previous key".  Maybe
a better error message would be along the lines of "cannot crumple
dictionary because of a mix of list and non-list keys"?  I dunno...

> +                return -1;
> +            }
> +            len++;
> +            if (val > max) {
> +                max = val;
> +            }
> +        } else {
> +            if (is_list == -1) {
> +                is_list = 0;
> +            } else if (is_list) {
> +                error_setg(errp,
> +                           "Key '%s' is for a dict, but previous key is "
> +                           "for a list", entry->key);

...same argument. If we can wordsmith something that makes sense, it
might work for both places.  Otherwise, I can live with your messages.


> +/**
> + * qdict_crumple:
> + *

Worth documenting the 'recursive' parameter?

> + * 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 merely one level of arrays
> + *
> + * { 'foo.0.bar': 'one', 'foo.0.wizz': '1',
> + *   'foo.1.bar': 'two', 'foo.1.wizz': '2' }
> + *
> + * =>
> + *
> + * {
> + *   'foo' => [

s/=>/:/

> + *      { 'bar': 'one', 'wizz': '1' }

s/$/,/

> + *      { 'bar': 'two', 'wizz': '2' }
> + *   ],
> + * }
> + *

Worth mentioning the escaping of '.' in key names?

> + */
> +QObject *qdict_crumple(QDict *src, bool recursive, Error **errp)
> +{
> +    const QDictEntry *entry, *next;
> +    QDict *two_level, *multi_level = NULL;
> +    QObject *dst = NULL, *child;
> +    ssize_t list_len;
> +    size_t i;
> +    char *prefix = NULL, *suffix = NULL;
> +
> +    two_level = qdict_new();
> +    entry = qdict_first(src);
> +
> +    /* Step 1: split our totally flat dict into a two level dict */

> +
> +    /* Step 2: optionally process the two level dict recursively
> +     * into a multi-level dict */
> +    if (recursive) {

> +
> +    /* Step 3: detect if we need to turn our dict into list */
> +    list_len = qdict_list_size(multi_level, errp);
> +    if (list_len < 0) {
> +        goto error;
> +    }
> +
> +    if (list_len) {
> +        dst = QOBJECT(qlist_new());
> +
> +        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);

Couldn't we assert() this, since it is a programming bug if
qdict_list_size() let us get this far but then the key disappeared?

Overall looks like it does the trick.


> +++ b/tests/check-qdict.c
> @@ -596,6 +596,140 @@ static void qdict_join_test(void)
>      QDECREF(dict2);
>  }
>  
> +
> +static void qdict_crumple_test_nonrecursive(void)
> +{

This only covers a single layer of collapse, but not turning a dict into
a list.  Is it also worth covering a case where no list indices are
involved, such as the four keys "a.b.d", "a.b.e", "a.c.d", "a.d.e" being
crumpled non-recursively into a single dict "a" with keys "b.d", "b.e",
"c.d", and "d.e"?

> +
> +static void qdict_crumple_test_recursive(void)
> +{
> +

This only covers a list of dict collapse, not a true multi-layer dict
collapse.  Is it also worth covering the same four keys as above, but
this time that dict "a" has keys "b" and "c", each of which is a dict in
turn with keys "d" and "e"?

> +static void qdict_crumple_test_empty(void)
> +{

So an empty dict is never crumpled to an empty list.  I guess that
shouldn't matter.

> +
> +static void qdict_crumple_test_bad_inputs(void)
> +{
> +    QDict *src;
> +    Error *error = NULL;
> +

> +
> +    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"));

I'd use "rule.a" and "rule.b" here, so that you aren't confusing this
with the earlier test that you can't mix list and dict.

I'd also add a negative test for "rule.1" without "rule.0" being invalid
(missing a list index).

I'll wait to give R-b until I get further into the series, and/or you
post a v4, but it's mostly there.
Daniel P. Berrangé March 22, 2016, 3:44 p.m. UTC | #2
On Mon, Mar 21, 2016 at 04:45:39PM -0600, Eric Blake wrote:
> On 03/10/2016 11:59 AM, Daniel P. Berrange wrote:

> > +    /* Unescape the '..' sequence into '.' */
> > +    for (i = 0, j = 0; (*prefix)[i] != '\0'; i++, j++) {
> > +        if ((*prefix)[i] == '.' &&
> > +            (*prefix)[i + 1] == '.') {
> 
> Technically, if (*prefix)[i] == '.', we could assert((*prefix)[i + 1] ==
> '.'), since the only way to get a '.' in prefix is via escaping.  For
> that matter, you could short-circuit (part of) the loop by doing a
> strchr for '.' (if not found, the loop is not needed; if found, start
> the reduction at that point rather on the bytes leading up to that point).

I'm not seeing obvious benefit in trying to short-circuit the loop
using a strchr, as both ways you still end up iterating over all
chars in the string - its just that you're hiding the iteration
in strchr instead.

> > +static ssize_t qdict_list_size(QDict *maybe_list, Error **errp)
> > +{
> > +    const QDictEntry *entry, *next;
> > +    ssize_t len = 0;
> > +    ssize_t max = -1;
> > +    int is_list = -1;
> > +    int64_t val;
> > +
> > +    entry = qdict_first(maybe_list);
> > +    while (entry != NULL) {
> > +        next = qdict_next(maybe_list, entry);
> > +
> > +        if (qemu_strtoll(entry->key, NULL, 10, &val) == 0) {
> > +            if (is_list == -1) {
> > +                is_list = 1;
> > +            } else if (!is_list) {
> > +                error_setg(errp,
> > +                           "Key '%s' is for a list, but previous key is "
> > +                           "for a dict", entry->key);
> 
> Keys are unsorted, so it's a bit hard to call it "previous key".  Maybe
> a better error message would be along the lines of "cannot crumple
> dictionary because of a mix of list and non-list keys"?  I dunno...

Yeah, I'll use

  "Cannot crumple a dictionary with a mix of 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,
> > +                           "Key '%s' is for a dict, but previous key is "
> > +                           "for a list", entry->key);
> 
> ...same argument. If we can wordsmith something that makes sense, it
> might work for both places.  Otherwise, I can live with your messages.


> > +++ b/tests/check-qdict.c
> > @@ -596,6 +596,140 @@ static void qdict_join_test(void)
> >      QDECREF(dict2);
> >  }
> >  
> > +
> > +static void qdict_crumple_test_nonrecursive(void)
> > +{
> 
> This only covers a single layer of collapse, but not turning a dict into
> a list.  Is it also worth covering a case where no list indices are
> involved, such as the four keys "a.b.d", "a.b.e", "a.c.d", "a.d.e" being
> crumpled non-recursively into a single dict "a" with keys "b.d", "b.e",
> "c.d", and "d.e"?

I'll add an explicit rule to test dict -> list conversion, and some
extra dict items here to cover proper nested dicts.

> 
> > +
> > +static void qdict_crumple_test_recursive(void)
> > +{
> > +
> 
> This only covers a list of dict collapse, not a true multi-layer dict
> collapse.  Is it also worth covering the same four keys as above, but
> this time that dict "a" has keys "b" and "c", each of which is a dict in
> turn with keys "d" and "e"?

I'll add some more dict items to properly cover nested dicts

> > +static void qdict_crumple_test_bad_inputs(void)
> > +{
> > +    QDict *src;
> > +    Error *error = NULL;
> > +
> 
> > +
> > +    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"));
> 
> I'd use "rule.a" and "rule.b" here, so that you aren't confusing this
> with the earlier test that you can't mix list and dict.

Good point.

> I'd also add a negative test for "rule.1" without "rule.0" being invalid
> (missing a list index).

Yep, I'll add that.


Regards,
Daniel
diff mbox

Patch

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..3a01fcc 100644
--- a/qobject/qdict.c
+++ b/qobject/qdict.c
@@ -682,6 +682,273 @@  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_list_size:
+ * @maybe_List: dict that may be only list elements
+ *
+ * Determine whether all keys in @maybe_list are
+ * valid list elements. They they are all valid,
+ * then this returns the number of elements. If
+ * they all look like non-numeric keys, then returns
+ * zero. If there is a mix of numeric and non-numeric
+ * keys, then an error is set as it is both a list
+ * and a dict at once.
+ *
+ * Returns: number of list elemets, 0 if a dict, -1 on error
+ */
+static ssize_t qdict_list_size(QDict *maybe_list, Error **errp)
+{
+    const QDictEntry *entry, *next;
+    ssize_t len = 0;
+    ssize_t max = -1;
+    int is_list = -1;
+    int64_t val;
+
+    entry = qdict_first(maybe_list);
+    while (entry != NULL) {
+        next = qdict_next(maybe_list, entry);
+
+        if (qemu_strtoll(entry->key, NULL, 10, &val) == 0) {
+            if (is_list == -1) {
+                is_list = 1;
+            } else if (!is_list) {
+                error_setg(errp,
+                           "Key '%s' is for a list, but previous key is "
+                           "for a dict", entry->key);
+                return -1;
+            }
+            len++;
+            if (val > max) {
+                max = val;
+            }
+        } else {
+            if (is_list == -1) {
+                is_list = 0;
+            } else if (is_list) {
+                error_setg(errp,
+                           "Key '%s' is for a dict, but previous key is "
+                           "for a list", entry->key);
+                return -1;
+            }
+        }
+
+        entry = next;
+    }
+
+    if (is_list == -1) {
+        is_list = 0;
+    }
+
+    if (len != (max + 1)) {
+        error_setg(errp, "List indexes are not continuous, "
+                   "saw %zd elements but %zd largest index",
+                   len, max);
+        return -1;
+    }
+
+    return is_list ? len : 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 merely 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;
+    ssize_t list_len;
+    size_t i;
+    char *prefix = NULL, *suffix = NULL;
+
+    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 */
+    list_len = qdict_list_size(multi_level, errp);
+    if (list_len < 0) {
+        goto error;
+    }
+
+    if (list_len) {
+        dst = QOBJECT(qlist_new());
+
+        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(qobject_to_qlist(dst), child);
+        }
+        QDECREF(multi_level);
+    } else {
+        dst = QOBJECT(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..ea67544 100644
--- a/tests/check-qdict.c
+++ b/tests/check-qdict.c
@@ -596,6 +596,140 @@  static void qdict_join_test(void)
     QDECREF(dict2);
 }
 
+
+static void qdict_crumple_test_nonrecursive(void)
+{
+    QDict *src, *dst, *rules;
+    QObject *child, *res;
+
+    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"));
+
+    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), ==, 1);
+
+    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"));
+
+    QDECREF(src);
+    QDECREF(dst);
+}
+
+
+static void qdict_crumple_test_recursive(void)
+{
+    QDict *src, *dst, *rule;
+    QObject *child, *res;
+    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"));
+
+    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, "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_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);
+
+    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.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 +877,15 @@  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/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);