[PATCH vkd3d v3 1/2] vkd3d-shader: Don't resize the buffer when there is enough free space.

[Matteo Bruni]

Signed-off-by: Matteo Bruni <mbruni(a)codeweavers.com>
---
v2: Handle rc < 0 case, use vkd3d_array_reserve().
v3: Fully make use of vkd3d_array_reserve() (thanks Henri).

 libs/vkd3d-shader/vkd3d_shader_main.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/libs/vkd3d-shader/vkd3d_shader_main.c b/libs/vkd3d-shader/vkd3d_shader_main.c
index 5d7cdf01..e7afbdfc 100644
--- a/libs/vkd3d-shader/vkd3d_shader_main.c
+++ b/libs/vkd3d-shader/vkd3d_shader_main.c
@@ -41,20 +41,14 @@ static void vkd3d_string_buffer_clear(struct vkd3d_string_buffer *buffer)
 
 static bool vkd3d_string_buffer_resize(struct vkd3d_string_buffer *buffer, int rc)
 {
-    unsigned int new_buffer_size = buffer->buffer_size * 2;
-    char *new_buffer;
+    unsigned int new_buffer_size = rc >= 0 ? buffer->content_size + rc + 1 : max(buffer->buffer_size * 2, 32);
 
-    new_buffer_size = max(new_buffer_size, 32);
-    while (rc > 0 && (unsigned int)rc >= new_buffer_size - buffer->content_size)
-        new_buffer_size *= 2;
-    if (!(new_buffer = vkd3d_realloc(buffer->buffer, new_buffer_size)))
+    if (!vkd3d_array_reserve((void **)&buffer->buffer, &buffer->buffer_size, new_buffer_size, 1))
     {
         ERR("Failed to grow buffer.\n");
         buffer->buffer[buffer->content_size] = '\0';
         return false;
     }
-    buffer->buffer = new_buffer;
-    buffer->buffer_size = new_buffer_size;
     return true;
 }
 
-- 
2.26.3

[PATCH vkd3d v3 2/2] vkd3d-shader: Allocate memory for a string buffer at init time.

[Matteo Bruni]

Signed-off-by: Matteo Bruni <mbruni(a)codeweavers.com>
---
It turns out that the solution in v2 didn't quite work because
preproc_add_macro() (and possibly others) copies a struct
vkd3d_string_buffer around. Rather than making that invalid, let's go
entirely the other way: always allocate a small buffer at init time
and, if that fails, simply crash: the situation is hopeless.

 libs/vkd3d-shader/vkd3d_shader_main.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/libs/vkd3d-shader/vkd3d_shader_main.c b/libs/vkd3d-shader/vkd3d_shader_main.c
index e7afbdfc..79bb9023 100644
--- a/libs/vkd3d-shader/vkd3d_shader_main.c
+++ b/libs/vkd3d-shader/vkd3d_shader_main.c
@@ -25,7 +25,11 @@ VKD3D_DEBUG_ENV_NAME("VKD3D_SHADER_DEBUG");
 
 void vkd3d_string_buffer_init(struct vkd3d_string_buffer *buffer)
 {
-    memset(buffer, 0, sizeof(*buffer));
+    buffer->buffer_size = 16;
+    buffer->content_size = 0;
+    buffer->buffer = vkd3d_malloc(buffer->buffer_size);
+    assert(buffer->buffer);
+    memset(buffer->buffer, 0, buffer->buffer_size);
 }
 
 void vkd3d_string_buffer_cleanup(struct vkd3d_string_buffer *buffer)
@@ -58,9 +62,6 @@ int vkd3d_string_buffer_vprintf(struct vkd3d_string_buffer *buffer, const char *
     va_list a;
     int rc;
 
-    if (!buffer->content_size && !vkd3d_string_buffer_resize(buffer, 32))
-        return -1;
-
     for (;;)
     {
         rem = buffer->buffer_size - buffer->content_size;
@@ -139,11 +140,6 @@ struct vkd3d_string_buffer *vkd3d_string_buffer_get(struct vkd3d_string_buffer_c
         if (!(buffer = vkd3d_malloc(sizeof(*buffer))))
             return NULL;
         vkd3d_string_buffer_init(buffer);
-        if (!vkd3d_string_buffer_resize(buffer, 1))
-        {
-            vkd3d_free(buffer);
-            return NULL;
-        }
     }
     else
     {
-- 
2.26.3

[Henri Verbeet]

On Wed, 15 Sept 2021 at 10:19, Matteo Bruni <mbruni(a)codeweavers.com> wrote:
> static bool vkd3d_string_buffer_resize(struct vkd3d_string_buffer *buffer, int rc)
>  {
> -    unsigned int new_buffer_size = buffer->buffer_size * 2;
> -    char *new_buffer;
> +    unsigned int new_buffer_size = rc >= 0 ? buffer->content_size + rc + 1 : max(buffer->buffer_size * 2, 32);
>
> -    new_buffer_size = max(new_buffer_size, 32);
> -    while (rc > 0 && (unsigned int)rc >= new_buffer_size - buffer->content_size)
> -        new_buffer_size *= 2;
> -    if (!(new_buffer = vkd3d_realloc(buffer->buffer, new_buffer_size)))
> +    if (!vkd3d_array_reserve((void **)&buffer->buffer, &buffer->buffer_size, new_buffer_size, 1))

Unfortunately this introduces warnings on 64-bit builds:

    libs/vkd3d-shader/vkd3d_shader_main.c:50:56: warning: passing
argument 2 of ‘vkd3d_array_reserve’ from incompatible pointer type
[-Wincompatible-pointer-types]
         if (!vkd3d_array_reserve((void **)&buffer->buffer,
&buffer->buffer_size, new_buffer_size, 1))
                                                            ^~~~~~~~~~~~~~~~~~~~