From 37acf433dbb2ef1d443c9ee09a315b0b4ce136d8 Mon Sep 17 00:00:00 2001
From: Dario Lombardo <lomato@gmail.com>
Date: Thu, 18 Feb 2016 11:32:07 +0100
Subject: wmem: add null-terminator support.

This change makes wmem_array more similar to GArray by adding
two functions that mimic the first two params of g_array_new().

Change-Id: Iaec999cd2e44f79f44d766be5d39741b73602e5a
Reviewed-on: https://code.wireshark.org/review/13989
Petri-Dish: Evan Huus <eapache@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Evan Huus <eapache@gmail.com>
---
 epan/wmem/wmem_array.c | 27 +++++++++++++++++++++++++++
 epan/wmem/wmem_array.h |  8 ++++++++
 epan/wmem/wmem_test.c  | 10 ++++++++++
 3 files changed, 45 insertions(+)

(limited to 'epan/wmem')

diff --git a/epan/wmem/wmem_array.c b/epan/wmem/wmem_array.c
index b4088fb051..6ac45989b2 100644
--- a/epan/wmem/wmem_array.c
+++ b/epan/wmem/wmem_array.c
@@ -45,6 +45,8 @@ struct _wmem_array_t {
 
     guint elem_count;
     guint alloc_count;
+
+    gboolean null_terminated;
 };
 
 wmem_array_t *
@@ -59,6 +61,7 @@ wmem_array_sized_new(wmem_allocator_t *allocator, gsize elem_size,
     array->elem_size   = elem_size;
     array->elem_count  = 0;
     array->alloc_count = alloc_count ? alloc_count : 1;
+    array->null_terminated = FALSE;
 
     array->buf = (guint8 *)wmem_alloc(array->allocator,
             array->elem_size * array->alloc_count);
@@ -98,6 +101,28 @@ wmem_array_grow(wmem_array_t *array, const guint to_add)
     array->alloc_count = new_alloc_count;
 }
 
+static void
+wmem_array_write_null_terminator(wmem_array_t *array)
+{
+    if (array->null_terminated) {
+        wmem_array_grow(array, 1);
+        memset(&array->buf[array->elem_count * array->elem_size], 0x0, array->elem_size);
+    }
+}
+
+void
+wmem_array_set_null_terminator(wmem_array_t *array)
+{
+    array->null_terminated = TRUE;
+    wmem_array_write_null_terminator(array);
+}
+
+void
+wmem_array_bzero(wmem_array_t *array)
+{
+    memset(array->buf, 0x0, array->elem_size * array->elem_count);
+}
+
 void
 wmem_array_append(wmem_array_t *array, const void *in, guint count)
 {
@@ -107,6 +132,8 @@ wmem_array_append(wmem_array_t *array, const void *in, guint count)
             count * array->elem_size);
 
     array->elem_count += count;
+
+    wmem_array_write_null_terminator(array);
 }
 
 void *
diff --git a/epan/wmem/wmem_array.h b/epan/wmem/wmem_array.h
index 2c5481950b..30738d696d 100644
--- a/epan/wmem/wmem_array.h
+++ b/epan/wmem/wmem_array.h
@@ -57,6 +57,14 @@ wmem_array_t *
 wmem_array_new(wmem_allocator_t *allocator, const gsize elem_size)
 G_GNUC_MALLOC;
 
+WS_DLL_PUBLIC
+void
+wmem_array_set_null_terminator(wmem_array_t *array);
+
+WS_DLL_PUBLIC
+void
+wmem_array_bzero(wmem_array_t *array);
+
 WS_DLL_PUBLIC
 void
 wmem_array_append(wmem_array_t *array, const void *in, guint count);
diff --git a/epan/wmem/wmem_test.c b/epan/wmem/wmem_test.c
index f57ae5ee78..b9da385181 100644
--- a/epan/wmem/wmem_test.c
+++ b/epan/wmem/wmem_test.c
@@ -475,6 +475,8 @@ wmem_test_array(void)
     unsigned int        i, j, k;
     guint32             val, *buf;
     guint32             vals[8];
+    guint32            *raw;
+    guint32            lastint;
 
     allocator = wmem_allocator_new(WMEM_ALLOCATOR_STRICT);
 
@@ -498,6 +500,7 @@ wmem_test_array(void)
     }
 
     array = wmem_array_sized_new(allocator, sizeof(guint32), 73);
+    wmem_array_set_null_terminator(array);
 
     for (i=0; i<CONTAINER_ITERS; i++) {
         for (j=0; j<8; j++) {
@@ -535,6 +538,13 @@ wmem_test_array(void)
     }
     g_assert(k == wmem_array_get_count(array));
 
+    lastint = 77;
+    wmem_array_append_one(array, lastint);
+
+    raw = (guint32*)wmem_array_get_raw(array);
+    g_assert(raw[wmem_array_get_count(array)] == 0);
+    g_assert(raw[wmem_array_get_count(array) - 1] == lastint);
+
     wmem_destroy_allocator(allocator);
 }
 
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