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From: Stefan Beller <sbeller@google.com>
To: sbeller@google.com
Cc: git@vger.kernel.org
Subject: [PATCH 1/9] string-list: add string_list_{pop, last} functions
Date: Mon, 17 Sep 2018 14:35:51 -0700	[thread overview]
Message-ID: <20180917213559.126404-2-sbeller@google.com> (raw)
In-Reply-To: <20180917213559.126404-1-sbeller@google.com>

Add a few functions to allow a string-list to be used as a stack:

 - string_list_last() lets a caller peek the string_list_item at the
   end of the string list.  The caller needs to be aware that it is
   borrowing a pointer, which can become invalid if/when the
   string_list is resized.

 - string_list_pop() removes the string_list_item at the end of
   the string list.

 - there is no string_list_push(); string_list_append() can be used
   in its place.

You can use them in this pattern:

    while (list.nr) {
        struct string_list_item *item = string_list_last(&list);

        work_on(item);
        string_list_pop(&list, free_util);
    }

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 string-list.c | 14 ++++++++++++++
 string-list.h | 15 +++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/string-list.c b/string-list.c
index 771c4550980..04db2b537c0 100644
--- a/string-list.c
+++ b/string-list.c
@@ -80,6 +80,20 @@ void string_list_remove(struct string_list *list, const char *string,
 	}
 }
 
+void string_list_pop(struct string_list *list, int free_util)
+{
+	if (list->nr == 0)
+		BUG("tried to remove an item from empty string list");
+
+	if (list->strdup_strings)
+		free(list->items[list->nr - 1].string);
+
+	if (free_util)
+		free(list->items[list->nr - 1].util);
+
+	list->nr--;
+}
+
 int string_list_has_string(const struct string_list *list, const char *string)
 {
 	int exact_match;
diff --git a/string-list.h b/string-list.h
index ff8f6094a33..15f2936e337 100644
--- a/string-list.h
+++ b/string-list.h
@@ -191,6 +191,21 @@ extern void string_list_remove(struct string_list *list, const char *string,
  */
 struct string_list_item *string_list_lookup(struct string_list *list, const char *string);
 
+/**
+ * Removes the last item from the list.
+ * The caller must ensure that the list is not empty.
+ */
+void string_list_pop(struct string_list *list, int free_util);
+
+/*
+ * Returns the last item of the list. As it returns the raw access, do not
+ * modify the list while holding onto the returned pointer.
+ */
+static inline struct string_list_item *string_list_last(struct string_list *list)
+{
+	return &list->items[list->nr - 1];
+}
+
 /*
  * Remove all but the first of consecutive entries with the same
  * string value.  If free_util is true, call free() on the util
-- 
2.19.0.397.gdd90340f6a-goog


  reply	other threads:[~2018-09-17 21:36 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-11 23:49 [PATCH 0/9] fetch: make sure submodule oids are fetched Stefan Beller
2018-09-11 23:49 ` [PATCH 1/9] string-list: add string_list_{pop, last} functions Stefan Beller
2018-09-12  2:24   ` Ramsay Jones
2018-09-12 17:52   ` Junio C Hamano
2018-09-11 23:49 ` [PATCH 2/9] sha1-array: provide oid_array_filter Stefan Beller
2018-09-12 18:02   ` Junio C Hamano
2018-09-11 23:49 ` [PATCH 3/9] submodule.c: fix indentation Stefan Beller
2018-09-12 18:02   ` Junio C Hamano
2018-09-11 23:49 ` [PATCH 4/9] submodule.c: sort changed_submodule_names before searching it Stefan Beller
2018-09-12 18:18   ` Junio C Hamano
2018-09-12 19:06     ` Stefan Beller
2018-09-11 23:49 ` [PATCH 5/9] submodule: move global changed_submodule_names into fetch submodule struct Stefan Beller
2018-09-11 23:49 ` [PATCH 6/9] submodule.c: do not copy around submodule list Stefan Beller
2018-09-12  2:25   ` Ramsay Jones
2018-09-11 23:49 ` [PATCH 7/9] submodule: fetch in submodules git directory instead of in worktree Stefan Beller
2018-09-12 18:36   ` Junio C Hamano
2018-09-13 19:29     ` Stefan Beller
2018-09-11 23:49 ` [PATCH 8/9] fetch: retry fetching submodules if sha1 were not fetched Stefan Beller
2018-09-12 19:03   ` Junio C Hamano
2018-09-11 23:49 ` [PATCH 9/9] builtin/fetch: check for submodule updates for non branch fetches Stefan Beller
2018-09-12 19:20   ` Junio C Hamano
2018-09-17 21:35 ` [PATCHv2 0/9] fetch: make sure submodule oids are fetched Stefan Beller
2018-09-17 21:35   ` Stefan Beller [this message]
2018-09-21 22:08     ` [PATCH] string-list: add string_list_{pop, last} functions Stefan Beller
2018-09-17 21:35   ` [PATCH 2/9] sha1-array: provide oid_array_filter Stefan Beller
2018-09-17 21:42     ` Stefan Beller
2018-09-17 21:35   ` [PATCH 3/9] submodule.c: fix indentation Stefan Beller
2018-09-17 21:35   ` [PATCH 4/9] submodule.c: sort changed_submodule_names before searching it Stefan Beller
2018-09-17 21:35   ` [PATCH 5/9] submodule: move global changed_submodule_names into fetch submodule struct Stefan Beller
2018-09-17 21:35   ` [PATCH 6/9] submodule.c: do not copy around submodule list Stefan Beller
2018-09-17 21:35   ` [PATCH 7/9] submodule: fetch in submodules git directory instead of in worktree Stefan Beller
2018-09-17 21:35   ` [PATCH 8/9] fetch: retry fetching submodules if needed objects were not fetched Stefan Beller
2018-09-17 21:35   ` [PATCH 9/9] builtin/fetch: check for submodule updates for non branch fetches Stefan Beller

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