beenull/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-11-23 16:10:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 6

LibGfx/GIF: Only use a FixedMemoryStream

Browse source 
This allows us to drop the data pointer in the `GIFLoadingContext`.
This commit is contained in:
Lucas CHOLLET 2023-07-14 17:45:19 -04:00 committed by Andreas Kling
parent 1192e46c09
commit b8bc84a3e8
Notes: sideshowbarker 2024-07-16 21:45:42 +09:00 
Author: https://github.com/LucasChollet
Commit: https://github.com/SerenityOS/serenity/commit/b8bc84a3e8
Pull-request: https://github.com/SerenityOS/serenity/pull/20029
2 changed files with 39 additions and 35 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

71
Userland/Libraries/LibGfx/ImageFormats/GIFLoader.cpp
View file

@ -59,6 +59,11 @@ struct LogicalScreen {
};
struct GIFLoadingContext {
GIFLoadingContext(FixedMemoryStream stream)
: stream(move(stream))
{
}
enum State {
NotDecoded = 0,
FrameDescriptorsLoaded,
@ -72,8 +77,9 @@ struct GIFLoadingContext {
FailedToLoadFrameDescriptors,
};
ErrorState error_state { NoError };
u8 const* data { nullptr };
size_t data_size { 0 };
FixedMemoryStream stream;
LogicalScreen logical_screen {};
u8 background_color_index { 0 };
Vector<NonnullOwnPtr<GIFImageDescriptor>> images {};
@ -377,24 +383,22 @@ static ErrorOr<void> decode_frame(GIFLoadingContext& context, size_t frame_index
static ErrorOr<void> load_gif_frame_descriptors(GIFLoadingContext& context)
{
if (context.data_size < 32)
if (TRY(context.stream.size()) < 32)
return Error::from_string_literal("Size too short for GIF frame descriptors");
FixedMemoryStream stream { { context.data, context.data_size } };
TRY(decode_gif_header(context.stream));
TRY(decode_gif_header(stream));
context.logical_screen.width = TRY(stream.read_value<LittleEndian<u16>>());
context.logical_screen.height = TRY(stream.read_value<LittleEndian<u16>>());
context.logical_screen.width = TRY(context.stream.read_value<LittleEndian<u16>>());
context.logical_screen.height = TRY(context.stream.read_value<LittleEndian<u16>>());
if (context.logical_screen.width > maximum_width_for_decoded_images || context.logical_screen.height > maximum_height_for_decoded_images) {
dbgln("This GIF is too large for comfort: {}x{}", context.logical_screen.width, context.logical_screen.height);
return Error::from_string_literal("This GIF is too large for comfort");
}
auto gcm_info = TRY(stream.read_value<u8>());
context.background_color_index = TRY(stream.read_value<u8>());
[[maybe_unused]] auto pixel_aspect_ratio = TRY(stream.read_value<u8>());
auto gcm_info = TRY(context.stream.read_value<u8>());
context.background_color_index = TRY(context.stream.read_value<u8>());
[[maybe_unused]] auto pixel_aspect_ratio = TRY(context.stream.read_value<u8>());
u8 bits_per_pixel = (gcm_info & 7) + 1;
int color_map_entry_count = 1;
@ -402,29 +406,29 @@ static ErrorOr<void> load_gif_frame_descriptors(GIFLoadingContext& context)
color_map_entry_count *= 2;
for (int i = 0; i < color_map_entry_count; ++i) {
u8 r = TRY(stream.read_value<u8>());
u8 g = TRY(stream.read_value<u8>());
u8 b = TRY(stream.read_value<u8>());
u8 r = TRY(context.stream.read_value<u8>());
u8 g = TRY(context.stream.read_value<u8>());
u8 b = TRY(context.stream.read_value<u8>());
context.logical_screen.color_map[i] = { r, g, b };
}
NonnullOwnPtr<GIFImageDescriptor> current_image = make<GIFImageDescriptor>();
for (;;) {
u8 sentinel = TRY(stream.read_value<u8>());
u8 sentinel = TRY(context.stream.read_value<u8>());
if (sentinel == '!') {
u8 extension_type = TRY(stream.read_value<u8>());
u8 extension_type = TRY(context.stream.read_value<u8>());
u8 sub_block_length = 0;
Vector<u8> sub_block {};
for (;;) {
sub_block_length = TRY(stream.read_value<u8>());
sub_block_length = TRY(context.stream.read_value<u8>());
if (sub_block_length == 0)
break;
TRY(sub_block.try_resize(sub_block.size() + sub_block_length));
TRY(stream.read_until_filled(sub_block.span().slice_from_end(sub_block_length)));
TRY(context.stream.read_until_filled(sub_block.span().slice_from_end(sub_block_length)));
}
if (extension_type == 0xF9) {
@ -470,12 +474,12 @@ static ErrorOr<void> load_gif_frame_descriptors(GIFLoadingContext& context)
context.images.append(move(current_image));
auto& image = context.images.last();
image->x = TRY(stream.read_value<LittleEndian<u16>>());
image->y = TRY(stream.read_value<LittleEndian<u16>>());
image->width = TRY(stream.read_value<LittleEndian<u16>>());
image->height = TRY(stream.read_value<LittleEndian<u16>>());
image->x = TRY(context.stream.read_value<LittleEndian<u16>>());
image->y = TRY(context.stream.read_value<LittleEndian<u16>>());
image->width = TRY(context.stream.read_value<LittleEndian<u16>>());
image->height = TRY(context.stream.read_value<LittleEndian<u16>>());
auto packed_fields = TRY(stream.read_value<u8>());
auto packed_fields = TRY(context.stream.read_value<u8>());
image->use_global_color_map = !(packed_fields & 0x80);
image->interlaced = (packed_fields & 0x40) != 0;
@ -484,24 +488,24 @@ static ErrorOr<void> load_gif_frame_descriptors(GIFLoadingContext& context)
size_t local_color_table_size = AK::exp2<size_t>((packed_fields & 7) + 1);
for (size_t i = 0; i < local_color_table_size; ++i) {
u8 r = TRY(stream.read_value<u8>());
u8 g = TRY(stream.read_value<u8>());
u8 b = TRY(stream.read_value<u8>());
u8 r = TRY(context.stream.read_value<u8>());
u8 g = TRY(context.stream.read_value<u8>());
u8 b = TRY(context.stream.read_value<u8>());
image->color_map[i] = { r, g, b };
}
}
image->lzw_min_code_size = TRY(stream.read_value<u8>());
image->lzw_min_code_size = TRY(context.stream.read_value<u8>());
u8 lzw_encoded_bytes_expected = 0;
for (;;) {
lzw_encoded_bytes_expected = TRY(stream.read_value<u8>());
lzw_encoded_bytes_expected = TRY(context.stream.read_value<u8>());
if (lzw_encoded_bytes_expected == 0)
break;
Array<u8, 256> buffer;
TRY(stream.read_until_filled(buffer.span().trim(lzw_encoded_bytes_expected)));
TRY(context.stream.read_until_filled(buffer.span().trim(lzw_encoded_bytes_expected)));
for (int i = 0; i < lzw_encoded_bytes_expected; ++i) {
image->lzw_encoded_bytes.append(buffer[i]);
@ -523,11 +527,9 @@ static ErrorOr<void> load_gif_frame_descriptors(GIFLoadingContext& context)
return {};
}
GIFImageDecoderPlugin::GIFImageDecoderPlugin(u8 const* data, size_t size)
GIFImageDecoderPlugin::GIFImageDecoderPlugin(FixedMemoryStream stream)
{
m_context = make<GIFLoadingContext>();
m_context->data = data;
m_context->data_size = size;
m_context = make<GIFLoadingContext>(move(stream));
}
GIFImageDecoderPlugin::~GIFImageDecoderPlugin() = default;
@ -556,7 +558,8 @@ bool GIFImageDecoderPlugin::sniff(ReadonlyBytes data)
ErrorOr<NonnullOwnPtr<ImageDecoderPlugin>> GIFImageDecoderPlugin::create(ReadonlyBytes data)
{
return adopt_nonnull_own_or_enomem(new (nothrow) GIFImageDecoderPlugin(data.data(), data.size()));
FixedMemoryStream stream { data };
return adopt_nonnull_own_or_enomem(new (nothrow) GIFImageDecoderPlugin(move(stream)));
}
bool GIFImageDecoderPlugin::is_animated()

3
Userland/Libraries/LibGfx/ImageFormats/GIFLoader.h
View file

@ -6,6 +6,7 @@
#pragma once
#include <AK/MemoryStream.h>
#include <LibGfx/Bitmap.h>
#include <LibGfx/ImageFormats/ImageDecoder.h>
@ -30,7 +31,7 @@ public:
virtual ErrorOr<Optional<ReadonlyBytes>> icc_data() override;
private:
GIFImageDecoderPlugin(u8 const*, size_t);
GIFImageDecoderPlugin(FixedMemoryStream);
OwnPtr<GIFLoadingContext> m_context;
};