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@Hermann-SW
Forked from jossef/script.js
Last active January 1, 2021 06:33
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calculate md5 hash in browser of large file
function calculateMD5Hash(file, bufferSize) {
var def = Q.defer();
var fileReader = new FileReader();
var fileSlicer = File.prototype.slice || File.prototype.mozSlice || File.prototype.webkitSlice;
var hashAlgorithm = new SparkMD5();
var totalParts = Math.ceil(file.size / bufferSize);
var currentPart = 0;
var startTime = new Date().getTime();
fileReader.onload = function(e) {
currentPart += 1;
def.notify({
currentPart: currentPart,
totalParts: totalParts
});
var buffer = e.target.result;
hashAlgorithm.appendBinary(buffer);
if (currentPart < totalParts) {
processNextPart();
return;
}
def.resolve({
hashResult: hashAlgorithm.end(),
duration: new Date().getTime() - startTime
});
};
fileReader.onerror = function(e) {
def.reject(e);
};
function processNextPart() {
var start = currentPart * bufferSize;
var end = Math.min(start + bufferSize, file.size);
fileReader.readAsBinaryString(fileSlicer.call(file, start, end));
}
processNextPart();
return def.promise;
}
function calculate() {
var input = document.getElementById('file');
if (!input.files.length) {
return;
}
var file = input.files[0];
var bufferSize = Math.pow(1024, 2) * 10; // 10MB
calculateMD5Hash(file, bufferSize).then(
function(result) {
// Success
console.log(result);
alert("duration: "+result.duration+"ms hashResult: "+result.hashResult);
},
function(err) {
// There was an error,
},
function(progress) {
// We get notified of the progress as it is executed
console.log(progress.currentPart, 'of', progress.totalParts, 'Total bytes:', progress.currentPart * bufferSize, 'of', progress.totalParts * bufferSize);
});
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/q.js/1.4.1/q.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/spark-md5/2.0.2/spark-md5.min.js"></script>
<script src="script.js"></script>
<div>
<input type="file" id="file"/>
<input type="button" onclick="calculate();" value="Calculate" class="btn primary" />
</div>
@Hermann-SW
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