Call realloc() less often because it is potentially slow.

Signed-off-by: Dominik Vogt <dvogt@ffm.tc.iot.dtag.de>
Signed-off-by: Jonas Fonseca <fonseca@diku.dk>

diff --git a/tig.c b/tig.c
index e5741d6..b3a4e8d 100644 (file)
--- a/tig.c
+++ b/tig.c
@@ -1429,9 +1429,10 @@ struct view {
        struct view *parent;
 
        /* Buffering */
-       unsigned long lines;    /* Total number of lines */
+       size_t lines;           /* Total number of lines */
        struct line *line;      /* Line index */
-       unsigned long line_size;/* Total number of allocated lines */
+       size_t line_alloc;      /* Total number of allocated lines */
+       size_t line_size;       /* Total number of used lines */
        unsigned int digits;    /* Number of digits in the lines member. */
 
        /* Loading */
@@ -2101,15 +2102,33 @@ begin_update(struct view *view)
        return TRUE;
 }
 
+#define ITEM_CHUNK_SIZE 256
+static void *
+realloc_items(void *mem, size_t *size, size_t new_size, size_t item_size)
+{
+       size_t num_chunks = *size / ITEM_CHUNK_SIZE;
+       size_t num_chunks_new = (new_size + ITEM_CHUNK_SIZE - 1) / ITEM_CHUNK_SIZE;
+
+       if (mem == NULL || num_chunks != num_chunks_new) {
+               *size = num_chunks_new * ITEM_CHUNK_SIZE;
+               mem = realloc(mem, *size * item_size);
+       }
+
+       return mem;
+}
+
 static struct line *
 realloc_lines(struct view *view, size_t line_size)
 {
-       struct line *tmp = realloc(view->line, sizeof(*view->line) * line_size);
+       size_t alloc = view->line_alloc;
+       struct line *tmp = realloc_items(view->line, &alloc, line_size,
+                                        sizeof(*view->line));
 
        if (!tmp)
                return NULL;
 
        view->line = tmp;
+       view->line_alloc = alloc;
        view->line_size = line_size;
        return view->line;
 }
@@ -3431,7 +3450,7 @@ status_open(struct view *view)
        for (i = 0; i < view->lines; i++)
                free(view->line[i].data);
        free(view->line);
-       view->lines = view->line_size = view->lineno = 0;
+       view->lines = view->line_alloc = view->line_size = view->lineno = 0;
        view->line = NULL;
 
        if (!realloc_lines(view, view->line_size + 6))
@@ -4830,18 +4849,21 @@ read_prompt(const char *prompt)
  * Repository references
  */
 
-static struct ref *refs;
-static size_t refs_size;
+static struct ref *refs = NULL;
+static size_t refs_alloc = 0;
+static size_t refs_size = 0;
 
 /* Id <-> ref store */
-static struct ref ***id_refs;
-static size_t id_refs_size;
+static struct ref ***id_refs = NULL;
+static size_t id_refs_alloc = 0;
+static size_t id_refs_size = 0;
 
 static struct ref **
 get_refs(char *id)
 {
        struct ref ***tmp_id_refs;
        struct ref **ref_list = NULL;
+       size_t ref_list_alloc = 0;
        size_t ref_list_size = 0;
        size_t i;
 
@@ -4849,7 +4871,8 @@ get_refs(char *id)
                if (!strcmp(id, id_refs[i][0]->id))
                        return id_refs[i];
 
-       tmp_id_refs = realloc(id_refs, (id_refs_size + 1) * sizeof(*id_refs));
+       tmp_id_refs = realloc_items(id_refs, &id_refs_alloc, id_refs_size + 1,
+                                   sizeof(*id_refs));
        if (!tmp_id_refs)
                return NULL;
 
@@ -4861,7 +4884,8 @@ get_refs(char *id)
                if (strcmp(id, refs[i].id))
                        continue;
 
-               tmp = realloc(ref_list, (ref_list_size + 1) * sizeof(*ref_list));
+               tmp = realloc_items(ref_list, &ref_list_alloc,
+                                   ref_list_size + 1, sizeof(*ref_list));
                if (!tmp) {
                        if (ref_list)
                                free(ref_list);
@@ -4932,7 +4956,7 @@ read_ref(char *id, size_t idlen, char *name, size_t namelen)
 
                return OK;
        }
-       refs = realloc(refs, sizeof(*refs) * (refs_size + 1));
+       refs = realloc_items(refs, &refs_alloc, refs_size + 1, sizeof(*refs));
        if (!refs)
                return ERR;