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From: "Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: Jeff King <peff@peff.net>, Elijah Newren <newren@gmail.com>,
	Elijah Newren <newren@gmail.com>,
	Elijah Newren <newren@gmail.com>
Subject: [PATCH v3 07/13] strmap: add more utility functions
Date: Mon, 02 Nov 2020 18:55:07 +0000
Message-ID: <42633b8d03008a159bc42bde319f50e87ddb00f6.1604343314.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.835.v3.git.git.1604343313.gitgitgadget@gmail.com>

From: Elijah Newren <newren@gmail.com>

This adds a number of additional convienence functions I want/need:
  * strmap_get_size()
  * strmap_empty()
  * strmap_remove()
  * strmap_for_each_entry()
  * strmap_get_entry()

I suspect the first four are self-explanatory.

strmap_get_entry() is similar to strmap_get() except that instead of just
returning the void* value that the string maps to, it returns the
strmap_entry that contains both the string and the void* value (or
NULL if the string isn't in the map).  This is helpful because it avoids
multiple lookups, e.g. in some cases a caller would need to call:
  * strmap_contains() to check that the map has an entry for the string
  * strmap_get() to get the void* value
  * <do some work to update the value>
  * strmap_put() to update/overwrite the value
If the void* pointer returned really is a pointer, then the last step is
unnecessary, but if the void* pointer is just cast to an integer then
strmap_put() will be needed.  In contrast, one can call strmap_get_entry()
and then:
  * check if the string was in the map by whether the pointer is NULL
  * access the value via entry->value
  * directly update entry->value
meaning that we can replace two or three hash table lookups with one.

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 strmap.c | 20 ++++++++++++++++++++
 strmap.h | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/strmap.c b/strmap.c
index 53f284eb20..829f1bc095 100644
--- a/strmap.c
+++ b/strmap.c
@@ -87,6 +87,11 @@ void *strmap_put(struct strmap *map, const char *str, void *data)
 	return old;
 }
 
+struct strmap_entry *strmap_get_entry(struct strmap *map, const char *str)
+{
+	return find_strmap_entry(map, str);
+}
+
 void *strmap_get(struct strmap *map, const char *str)
 {
 	struct strmap_entry *entry = find_strmap_entry(map, str);
@@ -97,3 +102,18 @@ int strmap_contains(struct strmap *map, const char *str)
 {
 	return find_strmap_entry(map, str) != NULL;
 }
+
+void strmap_remove(struct strmap *map, const char *str, int free_value)
+{
+	struct strmap_entry entry, *ret;
+	hashmap_entry_init(&entry.ent, strhash(str));
+	entry.key = str;
+	ret = hashmap_remove_entry(&map->map, &entry, ent, NULL);
+	if (!ret)
+		return;
+	if (free_value)
+		free(ret->value);
+	if (map->strdup_strings)
+		free((char*)ret->key);
+	free(ret);
+}
diff --git a/strmap.h b/strmap.h
index 96888c23ad..ee4307cca5 100644
--- a/strmap.h
+++ b/strmap.h
@@ -50,6 +50,12 @@ void strmap_clear(struct strmap *map, int free_values);
  */
 void *strmap_put(struct strmap *map, const char *str, void *data);
 
+/*
+ * Return the strmap_entry mapped by "str", or NULL if there is not such
+ * an item in map.
+ */
+struct strmap_entry *strmap_get_entry(struct strmap *map, const char *str);
+
 /*
  * Return the data pointer mapped by "str", or NULL if the entry does not
  * exist.
@@ -62,4 +68,34 @@ void *strmap_get(struct strmap *map, const char *str);
  */
 int strmap_contains(struct strmap *map, const char *str);
 
+/*
+ * Remove the given entry from the strmap.  If the string isn't in the
+ * strmap, the map is not altered.
+ */
+void strmap_remove(struct strmap *map, const char *str, int free_value);
+
+/*
+ * Return how many entries the strmap has.
+ */
+static inline unsigned int strmap_get_size(struct strmap *map)
+{
+	return hashmap_get_size(&map->map);
+}
+
+/*
+ * Return whether the strmap is empty.
+ */
+static inline int strmap_empty(struct strmap *map)
+{
+	return strmap_get_size(map) == 0;
+}
+
+/*
+ * iterate through @map using @iter, @var is a pointer to a type strmap_entry
+ */
+#define strmap_for_each_entry(mystrmap, iter, var)	\
+	for (var = hashmap_iter_first_entry_offset(&(mystrmap)->map, iter, 0); \
+		var; \
+		var = hashmap_iter_next_entry_offset(iter, 0))
+
 #endif /* STRMAP_H */
-- 
gitgitgadget


  parent reply index

Thread overview: 144+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-21 18:52 [PATCH 0/5] Add struct strmap and associated " Elijah Newren via GitGitGadget
2020-08-21 18:52 ` [PATCH 1/5] hashmap: add usage documentation explaining hashmap_free[_entries]() Elijah Newren via GitGitGadget
2020-08-21 19:22   ` Jeff King
2020-08-21 18:52 ` [PATCH 2/5] strmap: new utility functions Elijah Newren via GitGitGadget
2020-08-21 19:48   ` Jeff King
2020-08-21 18:52 ` [PATCH 3/5] strmap: add more " Elijah Newren via GitGitGadget
2020-08-21 19:58   ` Jeff King
2020-08-21 18:52 ` [PATCH 4/5] strmap: add strdup_strings option Elijah Newren via GitGitGadget
2020-08-21 20:01   ` Jeff King
2020-08-21 20:41     ` Elijah Newren
2020-08-21 21:03       ` Jeff King
2020-08-21 22:25         ` Elijah Newren
2020-08-28  7:08           ` Jeff King
2020-08-28 17:20             ` Elijah Newren
2020-08-21 18:52 ` [PATCH 5/5] strmap: add functions facilitating use as a string->int map Elijah Newren via GitGitGadget
2020-08-21 20:10   ` Jeff King
2020-08-21 20:51     ` Elijah Newren
2020-08-21 21:05       ` Jeff King
2020-08-21 20:16 ` [PATCH 0/5] Add struct strmap and associated utility functions Jeff King
2020-08-21 21:33   ` Elijah Newren
2020-08-21 22:28     ` Elijah Newren
2020-08-28  7:03     ` Jeff King
2020-08-28 15:29       ` Elijah Newren
2020-09-01  9:27         ` Jeff King
2020-10-13  0:40 ` [PATCH v2 00/10] " Elijah Newren via GitGitGadget
2020-10-13  0:40   ` [PATCH v2 01/10] hashmap: add usage documentation explaining hashmap_free[_entries]() Elijah Newren via GitGitGadget
2020-10-30 12:50     ` Jeff King
2020-10-30 19:55       ` Elijah Newren
2020-11-03 16:26         ` Jeff King
2020-11-03 16:48           ` Elijah Newren
2020-10-13  0:40   ` [PATCH v2 02/10] hashmap: adjust spacing to fix argument alignment Elijah Newren via GitGitGadget
2020-10-30 12:51     ` Jeff King
2020-10-13  0:40   ` [PATCH v2 03/10] hashmap: allow re-use after hashmap_free() Elijah Newren via GitGitGadget
2020-10-30 13:35     ` Jeff King
2020-10-30 15:37       ` Elijah Newren
2020-11-03 16:08         ` Jeff King
2020-11-03 16:16           ` Elijah Newren
2020-10-13  0:40   ` [PATCH v2 04/10] hashmap: introduce a new hashmap_partial_clear() Elijah Newren via GitGitGadget
2020-10-30 13:41     ` Jeff King
2020-10-30 16:03       ` Elijah Newren
2020-11-03 16:10         ` Jeff King
2020-10-13  0:40   ` [PATCH v2 05/10] strmap: new utility functions Elijah Newren via GitGitGadget
2020-10-30 14:12     ` Jeff King
2020-10-30 16:26       ` Elijah Newren
2020-10-13  0:40   ` [PATCH v2 06/10] strmap: add more " Elijah Newren via GitGitGadget
2020-10-30 14:23     ` Jeff King
2020-10-30 16:43       ` Elijah Newren
2020-11-03 16:12         ` Jeff King
2020-10-13  0:40   ` [PATCH v2 07/10] strmap: enable faster clearing and reusing of strmaps Elijah Newren via GitGitGadget
2020-10-30 14:27     ` Jeff King
2020-10-13  0:40   ` [PATCH v2 08/10] strmap: add functions facilitating use as a string->int map Elijah Newren via GitGitGadget
2020-10-30 14:39     ` Jeff King
2020-10-30 17:28       ` Elijah Newren
2020-11-03 16:20         ` Jeff King
2020-11-03 16:46           ` Elijah Newren
2020-10-13  0:40   ` [PATCH v2 09/10] strmap: add a strset sub-type Elijah Newren via GitGitGadget
2020-10-30 14:44     ` Jeff King
2020-10-30 18:02       ` Elijah Newren
2020-10-13  0:40   ` [PATCH v2 10/10] strmap: enable allocations to come from a mem_pool Elijah Newren via GitGitGadget
2020-10-30 14:56     ` Jeff King
2020-10-30 19:31       ` Elijah Newren
2020-11-03 16:24         ` Jeff King
2020-11-02 18:55   ` [PATCH v3 00/13] Add struct strmap and associated utility functions Elijah Newren via GitGitGadget
2020-11-02 18:55     ` [PATCH v3 01/13] hashmap: add usage documentation explaining hashmap_free[_entries]() Elijah Newren via GitGitGadget
2020-11-02 18:55     ` [PATCH v3 02/13] hashmap: adjust spacing to fix argument alignment Elijah Newren via GitGitGadget
2020-11-02 18:55     ` [PATCH v3 03/13] hashmap: allow re-use after hashmap_free() Elijah Newren via GitGitGadget
2020-11-02 18:55     ` [PATCH v3 04/13] hashmap: introduce a new hashmap_partial_clear() Elijah Newren via GitGitGadget
2020-11-02 18:55     ` [PATCH v3 05/13] hashmap: provide deallocation function names Elijah Newren via GitGitGadget
2020-11-02 18:55     ` [PATCH v3 06/13] strmap: new utility functions Elijah Newren via GitGitGadget
2020-11-02 18:55     ` Elijah Newren via GitGitGadget [this message]
2020-11-04 20:13       ` [PATCH v3 07/13] strmap: add more " Jeff King
2020-11-04 20:24         ` Elijah Newren
2020-11-02 18:55     ` [PATCH v3 08/13] strmap: enable faster clearing and reusing of strmaps Elijah Newren via GitGitGadget
2020-11-02 18:55     ` [PATCH v3 09/13] strmap: add functions facilitating use as a string->int map Elijah Newren via GitGitGadget
2020-11-04 20:21       ` Jeff King
2020-11-02 18:55     ` [PATCH v3 10/13] strmap: add a strset sub-type Elijah Newren via GitGitGadget
2020-11-04 20:31       ` Jeff King
2020-11-02 18:55     ` [PATCH v3 11/13] strmap: enable allocations to come from a mem_pool Elijah Newren via GitGitGadget
2020-11-02 18:55     ` [PATCH v3 12/13] strmap: take advantage of FLEXPTR_ALLOC_STR when relevant Elijah Newren via GitGitGadget
2020-11-04 20:43       ` Jeff King
2020-11-02 18:55     ` [PATCH v3 13/13] Use new HASHMAP_INIT macro to simplify hashmap initialization Elijah Newren via GitGitGadget
2020-11-04 20:48       ` Jeff King
2020-11-04 20:52     ` [PATCH v3 00/13] Add struct strmap and associated utility functions Jeff King
2020-11-04 22:20       ` Elijah Newren
2020-11-05  0:22     ` [PATCH v4 " Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 01/13] hashmap: add usage documentation explaining hashmap_free[_entries]() Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 02/13] hashmap: adjust spacing to fix argument alignment Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 03/13] hashmap: allow re-use after hashmap_free() Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 04/13] hashmap: introduce a new hashmap_partial_clear() Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 05/13] hashmap: provide deallocation function names Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 06/13] strmap: new utility functions Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 07/13] strmap: add more " Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 08/13] strmap: enable faster clearing and reusing of strmaps Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 09/13] strmap: add functions facilitating use as a string->int map Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 10/13] strmap: add a strset sub-type Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 11/13] strmap: enable allocations to come from a mem_pool Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 12/13] strmap: take advantage of FLEXPTR_ALLOC_STR when relevant Elijah Newren via GitGitGadget
2020-11-05  0:22       ` [PATCH v4 13/13] Use new HASHMAP_INIT macro to simplify hashmap initialization Elijah Newren via GitGitGadget
2020-11-05 13:29       ` [PATCH v4 00/13] Add struct strmap and associated utility functions Jeff King
2020-11-05 20:25         ` Junio C Hamano
2020-11-05 21:17           ` Jeff King
2020-11-05 21:22           ` Elijah Newren
2020-11-05 22:15             ` Junio C Hamano
2020-11-06  0:24       ` [PATCH v5 00/15] " Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 01/15] hashmap: add usage documentation explaining hashmap_free[_entries]() Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 02/15] hashmap: adjust spacing to fix argument alignment Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 03/15] hashmap: allow re-use after hashmap_free() Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 04/15] hashmap: introduce a new hashmap_partial_clear() Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 05/15] hashmap: provide deallocation function names Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 06/15] strmap: new utility functions Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 07/15] strmap: add more " Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 08/15] strmap: enable faster clearing and reusing of strmaps Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 09/15] strmap: add functions facilitating use as a string->int map Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 10/15] strmap: split create_entry() out of strmap_put() Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 11/15] strmap: add a strset sub-type Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 12/15] strmap: enable allocations to come from a mem_pool Elijah Newren via GitGitGadget
2020-11-11 17:33           ` Phillip Wood
2020-11-11 18:49             ` Elijah Newren
2020-11-11 19:01             ` Jeff King
2020-11-11 20:34               ` Chris Torek
2020-11-06  0:24         ` [PATCH v5 13/15] strmap: take advantage of FLEXPTR_ALLOC_STR when relevant Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 14/15] Use new HASHMAP_INIT macro to simplify hashmap initialization Elijah Newren via GitGitGadget
2020-11-06  0:24         ` [PATCH v5 15/15] shortlog: use strset from strmap.h Elijah Newren via GitGitGadget
2020-11-06  2:00         ` [PATCH v5 00/15] Add struct strmap and associated utility functions Junio C Hamano
2020-11-06  2:42           ` Elijah Newren
2020-11-06  2:48             ` Jeff King
2020-11-06 17:32               ` Junio C Hamano
2020-11-11 20:02         ` [PATCH v6 " Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 01/15] hashmap: add usage documentation explaining hashmap_free[_entries]() Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 02/15] hashmap: adjust spacing to fix argument alignment Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 03/15] hashmap: allow re-use after hashmap_free() Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 04/15] hashmap: introduce a new hashmap_partial_clear() Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 05/15] hashmap: provide deallocation function names Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 06/15] strmap: new utility functions Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 07/15] strmap: add more " Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 08/15] strmap: enable faster clearing and reusing of strmaps Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 09/15] strmap: add functions facilitating use as a string->int map Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 10/15] strmap: split create_entry() out of strmap_put() Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 11/15] strmap: add a strset sub-type Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 12/15] strmap: enable allocations to come from a mem_pool Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 13/15] strmap: take advantage of FLEXPTR_ALLOC_STR when relevant Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 14/15] Use new HASHMAP_INIT macro to simplify hashmap initialization Elijah Newren via GitGitGadget
2020-11-11 20:02           ` [PATCH v6 15/15] shortlog: use strset from strmap.h Elijah Newren via GitGitGadget
2020-11-11 20:07           ` [PATCH v6 00/15] Add struct strmap and associated utility functions Jeff King

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