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Mini Shell
Mini Shell
// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <numeric>
#include <vector>
#include <iostream>
#include <node.h>
#include <nan.h>
#include <vips/vips8>
#include "common.h"
#include "stats.h"
class StatsWorker : public Nan::AsyncWorker {
public:
StatsWorker(
Nan::Callback *callback, StatsBaton *baton, Nan::Callback *debuglog,
std::vector<v8::Local<v8::Object>> const buffersToPersist) :
Nan::AsyncWorker(callback, "sharp:StatsWorker"),
baton(baton), debuglog(debuglog),
buffersToPersist(buffersToPersist) {
// Protect Buffer objects from GC, keyed on index
std::accumulate(buffersToPersist.begin(), buffersToPersist.end(), 0,
[this](uint32_t index, v8::Local<v8::Object> const buffer) -> uint32_t {
SaveToPersistent(index, buffer);
return index + 1;
});
}
~StatsWorker() {}
const int STAT_MIN_INDEX = 0;
const int STAT_MAX_INDEX = 1;
const int STAT_SUM_INDEX = 2;
const int STAT_SQ_SUM_INDEX = 3;
const int STAT_MEAN_INDEX = 4;
const int STAT_STDEV_INDEX = 5;
const int STAT_MINX_INDEX = 6;
const int STAT_MINY_INDEX = 7;
const int STAT_MAXX_INDEX = 8;
const int STAT_MAXY_INDEX = 9;
void Execute() {
// Decrement queued task counter
g_atomic_int_dec_and_test(&sharp::counterQueue);
using Nan::New;
using Nan::Set;
using sharp::MaximumImageAlpha;
vips::VImage image;
sharp::ImageType imageType = sharp::ImageType::UNKNOWN;
try {
std::tie(image, imageType) = OpenInput(baton->input, baton->accessMethod);
} catch (vips::VError const &err) {
(baton->err).append(err.what());
}
if (imageType != sharp::ImageType::UNKNOWN) {
try {
vips::VImage stats = image.stats();
int const bands = image.bands();
for (int b = 1; b <= bands; b++) {
ChannelStats cStats(static_cast<int>(stats.getpoint(STAT_MIN_INDEX, b).front()),
static_cast<int>(stats.getpoint(STAT_MAX_INDEX, b).front()),
stats.getpoint(STAT_SUM_INDEX, b).front(), stats.getpoint(STAT_SQ_SUM_INDEX, b).front(),
stats.getpoint(STAT_MEAN_INDEX, b).front(), stats.getpoint(STAT_STDEV_INDEX, b).front(),
static_cast<int>(stats.getpoint(STAT_MINX_INDEX, b).front()),
static_cast<int>(stats.getpoint(STAT_MINY_INDEX, b).front()),
static_cast<int>(stats.getpoint(STAT_MAXX_INDEX, b).front()),
static_cast<int>(stats.getpoint(STAT_MAXY_INDEX, b).front()));
baton->channelStats.push_back(cStats);
}
// Image is not opaque when alpha layer is present and contains a non-mamixa value
if (sharp::HasAlpha(image)) {
double const minAlpha = static_cast<double>(stats.getpoint(STAT_MIN_INDEX, bands).front());
if (minAlpha != MaximumImageAlpha(image.interpretation())) {
baton->isOpaque = false;
}
}
// Estimate entropy via histogram of greyscale value frequency
baton->entropy = std::abs(image.colourspace(VIPS_INTERPRETATION_B_W)[0].hist_find().hist_entropy());
} catch (vips::VError const &err) {
(baton->err).append(err.what());
}
}
// Clean up
vips_error_clear();
vips_thread_shutdown();
}
void HandleOKCallback() {
using Nan::New;
using Nan::Set;
Nan::HandleScope();
v8::Local<v8::Value> argv[2] = { Nan::Null(), Nan::Null() };
if (!baton->err.empty()) {
argv[0] = Nan::Error(baton->err.data());
} else {
// Stats Object
v8::Local<v8::Object> info = New<v8::Object>();
v8::Local<v8::Array> channels = New<v8::Array>();
std::vector<ChannelStats>::iterator it;
int i = 0;
for (it = baton->channelStats.begin(); it < baton->channelStats.end(); it++, i++) {
v8::Local<v8::Object> channelStat = New<v8::Object>();
Set(channelStat, New("min").ToLocalChecked(), New<v8::Number>(it->min));
Set(channelStat, New("max").ToLocalChecked(), New<v8::Number>(it->max));
Set(channelStat, New("sum").ToLocalChecked(), New<v8::Number>(it->sum));
Set(channelStat, New("squaresSum").ToLocalChecked(), New<v8::Number>(it->squaresSum));
Set(channelStat, New("mean").ToLocalChecked(), New<v8::Number>(it->mean));
Set(channelStat, New("stdev").ToLocalChecked(), New<v8::Number>(it->stdev));
Set(channelStat, New("minX").ToLocalChecked(), New<v8::Number>(it->minX));
Set(channelStat, New("minY").ToLocalChecked(), New<v8::Number>(it->minY));
Set(channelStat, New("maxX").ToLocalChecked(), New<v8::Number>(it->maxX));
Set(channelStat, New("maxY").ToLocalChecked(), New<v8::Number>(it->maxY));
Set(channels, i, channelStat);
}
Set(info, New("channels").ToLocalChecked(), channels);
Set(info, New("isOpaque").ToLocalChecked(), New<v8::Boolean>(baton->isOpaque));
Set(info, New("entropy").ToLocalChecked(), New<v8::Number>(baton->entropy));
argv[1] = info;
}
// Dispose of Persistent wrapper around input Buffers so they can be garbage collected
std::accumulate(buffersToPersist.begin(), buffersToPersist.end(), 0,
[this](uint32_t index, v8::Local<v8::Object> const buffer) -> uint32_t {
GetFromPersistent(index);
return index + 1;
});
delete baton->input;
delete baton;
// Handle warnings
std::string warning = sharp::VipsWarningPop();
while (!warning.empty()) {
v8::Local<v8::Value> message[1] = { New(warning).ToLocalChecked() };
debuglog->Call(1, message, async_resource);
warning = sharp::VipsWarningPop();
}
// Return to JavaScript
callback->Call(2, argv, async_resource);
}
private:
StatsBaton* baton;
Nan::Callback *debuglog;
std::vector<v8::Local<v8::Object>> buffersToPersist;
};
/*
stats(options, callback)
*/
NAN_METHOD(stats) {
using sharp::AttrTo;
// Input Buffers must not undergo GC compaction during processing
std::vector<v8::Local<v8::Object>> buffersToPersist;
// V8 objects are converted to non-V8 types held in the baton struct
StatsBaton *baton = new StatsBaton;
v8::Local<v8::Object> options = info[0].As<v8::Object>();
// Input
baton->input = sharp::CreateInputDescriptor(sharp::AttrAs<v8::Object>(options, "input"), buffersToPersist);
baton->accessMethod = AttrTo<bool>(options, "sequentialRead") ? VIPS_ACCESS_SEQUENTIAL : VIPS_ACCESS_RANDOM;
// Function to notify of libvips warnings
Nan::Callback *debuglog = new Nan::Callback(sharp::AttrAs<v8::Function>(options, "debuglog"));
// Join queue for worker thread
Nan::Callback *callback = new Nan::Callback(info[1].As<v8::Function>());
Nan::AsyncQueueWorker(new StatsWorker(callback, baton, debuglog, buffersToPersist));
// Increment queued task counter
g_atomic_int_inc(&sharp::counterQueue);
}
Zerion Mini Shell 1.0