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Support setting PNG compression level. #308

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Support setting PNG compression level. #308

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9981b0f
Initial commit of extracted PNG creation.
kkoopa Jul 29, 2013
e67cdee
Added compression level argument to Canvas::toBuffer
kkoopa Jul 29, 2013
ae10e01
Cleaned up code and added the same fix to Canvas::StreamPngSync
kkoopa Jul 29, 2013
9e744ef
More cleanup.
kkoopa Jul 29, 2013
83f6a7e
Added another optional argument for setting row filters.
kkoopa Jul 29, 2013
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136 changes: 115 additions & 21 deletions src/Canvas.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@
//

#include "Canvas.h"
#include "PNG.h"
#include "CanvasRenderingContext2d.h"
#include <assert.h>
#include <stdlib.h>
Expand Down Expand Up @@ -44,6 +45,15 @@ Canvas::Initialize(Handle<Object> target) {
proto->SetAccessor(NanSymbol("type"), GetType);
proto->SetAccessor(NanSymbol("width"), GetWidth, SetWidth);
proto->SetAccessor(NanSymbol("height"), GetHeight, SetHeight);

proto->Set("PNG_NO_FILTERS", Uint32::New(PNG_NO_FILTERS));
proto->Set("PNG_FILTER_NONE", Uint32::New(PNG_FILTER_NONE));
proto->Set("PNG_FILTER_SUB", Uint32::New(PNG_FILTER_SUB));
proto->Set("PNG_FILTER_UP", Uint32::New(PNG_FILTER_UP));
proto->Set("PNG_FILTER_AVG", Uint32::New(PNG_FILTER_AVG));
proto->Set("PNG_FILTER_PAETH", Uint32::New(PNG_FILTER_PAETH));
proto->Set("PNG_ALL_FILTERS", Uint32::New(PNG_ALL_FILTERS));

target->Set(NanSymbol("Canvas"), ctor->GetFunction());
}

Expand Down Expand Up @@ -128,31 +138,31 @@ NAN_SETTER(Canvas::SetHeight) {
static cairo_status_t
toBuffer(void *c, const uint8_t *data, unsigned len) {
closure_t *closure = (closure_t *) c;

// Olaf: grow buffer

if (closure->len + len > closure->max_len) {
uint8_t *data;
unsigned max;

// round to the nearest multiple of 1024 bytes
max = (closure->max_len + len + 1023) & ~1023;

unsigned max = closure->max_len;

do {
max *= 2;
} while (closure->len + len > max);

data = (uint8_t *) realloc(closure->data, max);
if (!data) return CAIRO_STATUS_NO_MEMORY;
closure->data = data;
closure->max_len = max;
}

memcpy(closure->data + closure->len, data, len);
closure->len += len;

return CAIRO_STATUS_SUCCESS;
}

/*
* EIO toBuffer callback.
*/

#if NODE_VERSION_AT_LEAST(0, 6, 0)
void
Canvas::ToBufferAsync(uv_work_t *req) {
Expand All @@ -165,11 +175,11 @@ Canvas::EIO_ToBuffer(eio_req *req) {
#endif
closure_t *closure = (closure_t *) req->data;

closure->status = cairo_surface_write_to_png_stream(
closure->status = canvas_write_to_png_stream(
closure->canvas->surface()
, toBuffer
, closure);

#if !NODE_VERSION_AT_LEAST(0, 5, 4)
return 0;
#endif
Expand Down Expand Up @@ -209,20 +219,22 @@ Canvas::EIO_AfterToBuffer(eio_req *req) {
delete closure->pfn;
closure_destroy(closure);
free(closure);

#if !NODE_VERSION_AT_LEAST(0, 6, 0)
return 0;
#endif
}

/*
* Convert PNG data to a node::Buffer, async when a
* Convert PNG data to a node::Buffer, async when a
* callback function is passed.
*/

NAN_METHOD(Canvas::ToBuffer) {
NanScope();
cairo_status_t status;
uint32_t compression_level = 6;
uint32_t filter = PNG_ALL_FILTERS;
Canvas *canvas = ObjectWrap::Unwrap<Canvas>(args.This());

// TODO: async / move this out
Expand All @@ -234,10 +246,48 @@ NAN_METHOD(Canvas::ToBuffer) {
NanReturnValue(buf);
}

if (args.Length() > 1 && !(args[1]->StrictEquals(Undefined()) && args[2]->StrictEquals(Undefined()))) {
if (!args[1]->StrictEquals(Undefined())) {
bool good = true;
if (args[1]->IsNumber()) {
compression_level = args[1]->Uint32Value();
} else if (args[1]->IsString()) {
if (args[1]->StrictEquals(String::New("0"))) {
compression_level = 0;
} else {
uint32_t tmp = args[1]->Uint32Value();
if (tmp == 0) {
good = false;
} else {
compression_level = tmp;
}
}
} else {
good = false;
}

if (good) {
if (compression_level > 9) {
return NanThrowRangeError("Allowed compression levels lie in the range [0, 9].");
}
} else {
return NanThrowTypeError("Compression level must be a number.");
}
}

if (!args[2]->StrictEquals(Undefined())) {
if (args[2]->IsUint32()) {
filter = args[1]->Uint32Value();
} else {
return NanThrowTypeError("Invalid filter value.");
}
}
}

// Async
if (args[0]->IsFunction()) {
closure_t *closure = (closure_t *) malloc(sizeof(closure_t));
status = closure_init(closure, canvas);
status = closure_init(closure, canvas, compression_level, filter);

// ensure closure is ok
if (status) {
Expand All @@ -249,7 +299,7 @@ NAN_METHOD(Canvas::ToBuffer) {
// TODO: only one callback fn in closure
canvas->Ref();
closure->pfn = new NanCallback(args[0].As<Function>());

#if NODE_VERSION_AT_LEAST(0, 6, 0)
uv_work_t* req = new uv_work_t;
req->data = closure;
Expand All @@ -258,12 +308,12 @@ NAN_METHOD(Canvas::ToBuffer) {
eio_custom(EIO_ToBuffer, EIO_PRI_DEFAULT, EIO_AfterToBuffer, closure);
ev_ref(EV_DEFAULT_UC);
#endif

NanReturnUndefined();
// Sync
} else {
closure_t closure;
status = closure_init(&closure, canvas);
status = closure_init(&closure, canvas, compression_level, filter);

// ensure closure is ok
if (status) {
Expand All @@ -272,7 +322,7 @@ NAN_METHOD(Canvas::ToBuffer) {
}

TryCatch try_catch;
status = cairo_surface_write_to_png_stream(canvas->surface(), toBuffer, &closure);
status = canvas_write_to_png_stream(canvas->surface(), toBuffer, &closure);

if (try_catch.HasCaught()) {
closure_destroy(&closure);
Expand Down Expand Up @@ -311,16 +361,60 @@ streamPNG(void *c, const uint8_t *data, unsigned len) {

NAN_METHOD(Canvas::StreamPNGSync) {
NanScope();
uint32_t compression_level = 6;
uint32_t filter = PNG_ALL_FILTERS;
// TODO: async as well
if (!args[0]->IsFunction())
return NanThrowTypeError("callback function required");

if (args.Length() > 1 && !(args[1]->StrictEquals(Undefined()) && args[2]->StrictEquals(Undefined()))) {
if (!args[1]->StrictEquals(Undefined())) {
bool good = true;
if (args[1]->IsNumber()) {
compression_level = args[1]->Uint32Value();
} else if (args[1]->IsString()) {
if (args[1]->StrictEquals(String::New("0"))) {
compression_level = 0;
} else {
uint32_t tmp = args[1]->Uint32Value();
if (tmp == 0) {
good = false;
} else {
compression_level = tmp;
}
}
} else {
good = false;
}

if (good) {
if (compression_level > 9) {
return NanThrowRangeError("Allowed compression levels lie in the range [0, 9].");
}
} else {
return NanThrowTypeError("Compression level must be a number.");
}
}

if (!args[2]->StrictEquals(Undefined())) {
if (args[2]->IsUint32()) {
filter = args[1]->Uint32Value();
} else {
return NanThrowTypeError("Invalid filter value.");
}
}
}


Canvas *canvas = ObjectWrap::Unwrap<Canvas>(args.This());
closure_t closure;
closure.fn = Handle<Function>::Cast(args[0]);
closure.compression_level = compression_level;
closure.filter = filter;

TryCatch try_catch;
cairo_status_t status = cairo_surface_write_to_png_stream(canvas->surface(), streamPNG, &closure);

cairo_status_t status = canvas_write_to_png_stream(canvas->surface(), streamPNG, &closure);

if (try_catch.HasCaught()) {
NanReturnValue(try_catch.ReThrow());
Expand Down Expand Up @@ -381,7 +475,7 @@ Canvas::Canvas(int w, int h, canvas_type_t t): ObjectWrap() {
if (CANVAS_TYPE_PDF == t) {
_closure = malloc(sizeof(closure_t));
assert(_closure);
cairo_status_t status = closure_init((closure_t *) _closure, this);
cairo_status_t status = closure_init((closure_t *) _closure, this, 0, PNG_NO_FILTERS);
assert(status == CAIRO_STATUS_SUCCESS);
_surface = cairo_pdf_surface_create_for_stream(toBuffer, _closure, w, h);
} else {
Expand Down
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