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Add support for the operations exposed by the 'sharp' library. Fixes #6.
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NOTE: The test doesn't work yet, but it seems to be working fine when just getFilterInfosAndTargetContentTypeFromQueryString from an external app.
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@papandreou
papandreou committed Oct 22, 2014
1 parent 236225d commit b624be0
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Showing 3 changed files with 143 additions and 73 deletions.
198 changes: 127 additions & 71 deletions lib/getFilterInfosAndTargetContentTypeFromQueryString.js
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Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
var Stream = require('stream'),
gm = require('gm'),
isGmOperationByName = {},
sharp = require('sharp'),
isOperationByEngineNameAndName = {gm: {}, sharp: {}},
filterConstructorByOperationName = {};

['PngQuant', 'PngCrush', 'OptiPng', 'JpegTran', 'Inkscape', 'SvgFilter'].forEach(function (constructorName) {
Expand All @@ -13,84 +14,115 @@ var Stream = require('stream'),
});

Object.keys(gm.prototype).forEach(function (propertyName) {
if (!/^_|^(?:size|orientation|format|depth|color|res|filesize|identity|write|stream)$/.test(propertyName) &&
if (!/^_|^(?:emit|.*Listeners?|on|once|size|orientation|format|depth|color|res|filesize|identity|write|stream)$/.test(propertyName) &&
typeof gm.prototype[propertyName] === 'function') {
isGmOperationByName[propertyName] = true;
isOperationByEngineNameAndName.gm[propertyName] = true;
}
});

['resize', 'extract', 'sequentialRead', 'crop', 'max', 'background', 'embed', 'flatten', 'rotate', 'flip', 'flop', 'withoutEnlargement', 'sharpen', 'interpolateWith', 'gamma', 'grayscale', 'greyscale', 'jpeg', 'webp', 'quality', 'progressive', 'withMetadata', 'compressionLevel'].forEach(function (sharpOperationName) {
isOperationByEngineNameAndName.sharp[sharpOperationName] = true;
});

var engineNamesByOperationName = {};

Object.keys(isOperationByEngineNameAndName).forEach(function (engineName) {
Object.keys(isOperationByEngineNameAndName[engineName]).forEach(function (operationName) {
(engineNamesByOperationName[operationName] = engineNamesByOperationName[operationName] || []).push(engineName);
});
});

module.exports = function getFilterInfosAndTargetContentTypeFromQueryString(queryString, options) {
options = options || {};
var filters = options.filters || {},
filterInfos = [],
gmOperations = [],
defaultEngineName = options.defaultEngineName || 'gm',
currentEngineName,
operations = [],
operationNames = [],
usedQueryStringFragments = [],
leftOverQueryStringFragments = [],
targetContentType;

function flushGmOperations() {
if (gmOperations.length > 0) {
var gmOperationsForThisInstance = [].concat(gmOperations);
operationNames.push('gm');
filterInfos.push({
operationName: 'gm',
usedQueryStringFragments: gmOperations.map(function (gmOperation) {
return gmOperation.usedQueryStringFragment;
}),
create: function () {
// For some reason the gm module doesn't expose itself as a readable/writable stream,
// so we need to wrap it into one:
function flushOperations() {
if (operations.length > 0) {
if (currentEngineName === 'sharp') {
var sharpOperationsForThisInstance = [].concat(operations);
operationNames.push('sharp');
filterInfos.push({
operationName: 'sharp',
usedQueryStringFragments: operations.map(function (operation) {
return operation.usedQueryStringFragment;
}),
create: function () {
return sharpOperationsForThisInstance.reduce(function (sharpInstance, sharpOperation) {
return sharpInstance[sharpOperation.name].apply(sharpInstance, sharpOperation.args)
}, sharp());
}
});
} else if (currentEngineName === 'gm') {
var gmOperationsForThisInstance = [].concat(operations);
operationNames.push('gm');
filterInfos.push({
operationName: 'gm',
usedQueryStringFragments: operations.map(function (gmOperation) {
return gmOperation.usedQueryStringFragment;
}),
create: function () {
// For some reason the gm module doesn't expose itself as a readable/writable stream,
// so we need to wrap it into one:

var readStream = new Stream();
readStream.readable = true;
var readStream = new Stream();
readStream.readable = true;

var readWriteStream = new Stream();
readWriteStream.readable = readWriteStream.writable = true;
var spawned = false;
var readWriteStream = new Stream();
readWriteStream.readable = readWriteStream.writable = true;
var spawned = false;

readWriteStream.write = function (chunk) {
if (!spawned) {
spawned = true;
var gmInstance = gm(readStream);
gmOperationsForThisInstance.forEach(function (gmOperation) {
gmInstance = gmInstance[gmOperation.name].apply(gmInstance, gmOperation.args);
});
var seenData = false,
hasEnded = false;
gmInstance.stream(function (err, stdout, stderr) {
if (err) {
hasEnded = true;
return readWriteStream.emit('error', err);
}
stdout.on('data', function (chunk) {
seenData = true;
readWriteStream.emit('data', chunk);
}).on('end', function () {
if (!hasEnded) {
if (seenData) {
readWriteStream.emit('end');
} else {
readWriteStream.emit('error', new Error('The gm stream ended without emitting any data'));
}
readWriteStream.write = function (chunk) {
if (!spawned) {
spawned = true;
var seenData = false,
hasEnded = false;
gmOperationsForThisInstance.reduce(function (gmInstance, gmOperation) {
return gmInstance[gmOperation.name].apply(gmInstance, gmOperation.args);
}, gm(readStream)).stream(function (err, stdout, stderr) {
if (err) {
hasEnded = true;
return readWriteStream.emit('error', err);
}
stdout.on('data', function (chunk) {
seenData = true;
readWriteStream.emit('data', chunk);
}).on('end', function () {
if (!hasEnded) {
if (seenData) {
readWriteStream.emit('end');
} else {
readWriteStream.emit('error', new Error('The gm stream ended without emitting any data'));
}
hasEnded = true;
}
});
});
});
}
readStream.emit('data', chunk);
};
readWriteStream.end = function (chunk) {
if (chunk) {
readWriteStream.write(chunk);
}
readStream.emit('end');
};
return readWriteStream;
}
});
gmOperations = [];
}
readStream.emit('data', chunk);
};
readWriteStream.end = function (chunk) {
if (chunk) {
readWriteStream.write(chunk);
}
readStream.emit('end');
};
return readWriteStream;
}
});
} else {
throw new Error('Internal error');
}
operations = [];
}
currentEngineName = undefined;
}

queryString.split('&').forEach(function (keyValuePair) {
Expand All @@ -112,7 +144,7 @@ module.exports = function getFilterInfosAndTargetContentTypeFromQueryString(quer
}) : [];

if (filters[operationName]) {
flushGmOperations();
flushOperations();
var filterInfo = filters[operationName](operationArgs, {
inputContentType: targetContentType,
numPreceedingFilters: filterInfos.length
Expand All @@ -124,27 +156,51 @@ module.exports = function getFilterInfosAndTargetContentTypeFromQueryString(quer
targetContentType = filterInfo.outputContentType;
}
filterInfos.push(filterInfo);
operationNames.push(operationNameLowerCase);
operationNames.push(operationName);
usedQueryStringFragments.push(keyValuePair);
} else {
leftOverQueryStringFragments.push(keyValuePair);
}
} else if (isGmOperationByName[operationName] && filters.gm !== false) {
if (operationName === 'setFormat' && operationArgs.length > 0) {
var targetFormat = operationArgs[0].toLowerCase();
if (targetFormat === 'jpg') {
targetFormat = 'jpeg';
} else if (isOperationByEngineNameAndName[operationName]) {
usedQueryStringFragments.push(keyValuePair);
flushOperations();
defaultEngineName = operationName;
} else if (engineNamesByOperationName[operationName]) {
// Check if at least one of the engines supporting this operation is allowed
var candidateEngineNames = engineNamesByOperationName[operationName].filter(function (engineName) {
return filters[engineName] !== false;
});
if (candidateEngineNames.length > 0) {
if (currentEngineName && !isOperationByEngineNameAndName[currentEngineName]) {
flushOperations();
}
targetContentType = 'image/' + targetFormat;

if (!currentEngineName || candidateEngineNames.indexOf(currentEngineName) === -1) {
if (candidateEngineNames.indexOf(defaultEngineName) !== -1) {
currentEngineName = defaultEngineName;
} else {
currentEngineName = candidateEngineNames[0];
}
}

if (operationName === 'setFormat' && operationArgs.length > 0) {
var targetFormat = operationArgs[0].toLowerCase();
if (targetFormat === 'jpg') {
targetFormat = 'jpeg';
}
targetContentType = 'image/' + targetFormat;
} else if (operationName === 'jpeg' || operationName === 'png' || operationName === 'webp') {
targetContentType = 'image/' + operationName;
}
operations.push({name: operationName, args: operationArgs, usedQueryStringFragment: keyValuePair});
usedQueryStringFragments.push(keyValuePair);
}
gmOperations.push({name: operationName, args: operationArgs, usedQueryStringFragment: keyValuePair});
usedQueryStringFragments.push(keyValuePair);
} else {
var operationNameLowerCase = operationName.toLowerCase(),
FilterConstructor = filterConstructorByOperationName[operationNameLowerCase];
if (FilterConstructor && filters[operationNameLowerCase] !== false) {
operationNames.push(operationNameLowerCase);
flushGmOperations();
flushOperations();
if (operationNameLowerCase === 'svgfilter' && options.rootPath && options.sourceFilePath) {
operationArgs.push('--root', 'file://' + options.rootPath, '--url', 'file://' + options.sourceFilePath);
}
Expand All @@ -170,7 +226,7 @@ module.exports = function getFilterInfosAndTargetContentTypeFromQueryString(quer
}
}
});
flushGmOperations();
flushOperations();

return {
targetContentType: targetContentType,
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3 changes: 2 additions & 1 deletion package.json
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Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,8 @@
"optipng": "0.1.1",
"passerror": "0.0.1",
"pngcrush": "0.1.0",
"pngquant": "0.3.0"
"pngquant": "0.3.0",
"sharp": "0.7.0"
},
"optionalDependencies": {
"svgfilter": "0.4.0"
Expand Down
15 changes: 14 additions & 1 deletion test/processImage.js
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Original file line number Diff line number Diff line change
Expand Up @@ -113,7 +113,7 @@ describe('test server', function () {
});

it('should run the image through graphicsmagick when methods exposed by the gm module are added as CGI params', function (done) {
request({url: baseUrl + '/turtle.jpg?resize=340,300', encoding: null}, passError(done, function (response, body) {
request({url: baseUrl + '/turtle.jpg?gm&resize=340,300', encoding: null}, passError(done, function (response, body) {
expect(response.statusCode, 'to equal', 200);
expect(response.headers['content-type'], 'to equal', 'image/jpeg');
expect(body.slice(0, 10).toString(), 'to equal', new Buffer([0xff, 0xd8, 0xff, 0xe0, 0x00, 0x10, 0x4a, 0x46, 0x49, 0x46]).toString());
Expand All @@ -128,6 +128,19 @@ describe('test server', function () {
}));
});

it.skip('should run the image through sharp when methods exposed by the sharp module are added as CGI params', function (done) {
request({url: baseUrl + '/turtle.jpg?sharp&resize=340,300', encoding: null}, passError(done, function (response, body) {
expect(response.statusCode, 'to equal', 200);
expect(response.headers['content-type'], 'to equal', 'image/jpeg');
getImageMetadataFromBuffer(body, passError(done, function (metadata) {
expect(metadata.format, 'to equal', 'JPEG');
expect(metadata.size.width, 'to equal', 340);
expect(metadata.size.height, 'to equal', 300);
done();
}));
}));
});

it('should run the image through svgfilter when the svgfilter parameter is specified', function (done) {
request({url: baseUrl + '/dialog-information.svg?svgfilter=--runScript=addBogusElement.js,--bogusElementId=theBogusElementId'}, passError(done, function (response, svgText) {
expect(response.statusCode, 'to equal', 200);
Expand Down

6 comments on commit b624be0

@Munter
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@Munter Munter commented on b624be0 Oct 22, 2014

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This is pretty awesome. Does this also incidentally remove the gm requirement on resizing images?

@papandreou
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It could. Both modules expose resize with the same signature. My intention is to make sharp the default engine once I have that test passing. Then the graphicsmagick binary would only be required for the operations that aren't supported by sharp.

@lovell
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@lovell lovell commented on b624be0 Oct 22, 2014

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Hello, sharp author here, thanks for using it with your express-processimage module.

"the operations that aren't supported by sharp"

Please feel free to open issues (or +1 existing issues) for any additional features you need.

I'm currently working on lovell/sharp#42 which should remove the overhead of manually installing libvips.

@papandreou
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@lovell Thanks for getting in touch! Really liking your library. I sent you a couple of PRs for the very minor issues I found.

Good to hear that you're working on lovell/sharp#42. That one gets my vote. It would be a great win not to have any non-npm prerequisites.

@Munter Yeah, that means we're not quite there yet wrt. resize without having to install separate libraries. It's either graphicsmagick or libvips. I guess I should make sharp an optional dependency until we can deliver that.

@Munter
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@Munter Munter commented on b624be0 Oct 23, 2014

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We have experience with making things optional, so that's fine.

@lovell I am very happy to hear that you are putting in time on trying to remove the non-npm dependencies. This module is used in the larger contexts of assetgraph-builder and livestyle, which both require some time investment by the user in order to install the external dependencies. Any one of these we can remove means a better user impression and higher adoption :)

@lovell
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@lovell lovell commented on b624be0 Oct 23, 2014

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Tak!

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