Sakurai/pdf.js
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make the getBytes/peekBytes methods of Stream/DecodeStream/ChunkedStream able to return Uint8ClampedArrays

Browse Source 
The built-in image decoders are already returning data as `Uint8ClampedArray`, and subsequently the JPEG/JBIG2/JPX streams are as well. However, for general streams we obviously don't want to force the use of `Uint8ClampedArray` unless an "Image" is actually being decoded.
Hence this patch, which adds a parameter that allows the caller of the `getBytes`/`peekBytes` methods to force a `Uint8ClampedArray` (rather than a `Uint8Array`) to be returned.
This commit is contained in:
Jonas Jenwald 2018-06-11 17:25:30 +02:00
parent 2030d1718f
commit 32367c5968
3 changed files with 32 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
src/core/chunked_stream.js
View File

@ -181,16 +181,17 @@ var ChunkedStream = (function ChunkedStreamClosure() {
return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
},
// returns subarray of original buffer
// should only be read
getBytes: function ChunkedStream_getBytes(length) {
// Returns subarray of original buffer, should only be read.
getBytes(length, forceClamped = false) {
var bytes = this.bytes;
var pos = this.pos;
var strEnd = this.end;
if (!length) {
this.ensureRange(pos, strEnd);
return bytes.subarray(pos, strEnd);
let subarray = bytes.subarray(pos, strEnd);
// `this.bytes` is always a `Uint8Array` here.
return (forceClamped ? new Uint8ClampedArray(subarray) : subarray);
}
var end = pos + length;
@ -200,7 +201,9 @@ var ChunkedStream = (function ChunkedStreamClosure() {
this.ensureRange(pos, end);
this.pos = end;
return bytes.subarray(pos, end);
let subarray = bytes.subarray(pos, end);
// `this.bytes` is always a `Uint8Array` here.
return (forceClamped ? new Uint8ClampedArray(subarray) : subarray);
},
peekByte: function ChunkedStream_peekByte() {
@ -209,8 +212,8 @@ var ChunkedStream = (function ChunkedStreamClosure() {
return peekedByte;
},
peekBytes: function ChunkedStream_peekBytes(length) {
var bytes = this.getBytes(length);
peekBytes(length, forceClamped = false) {
var bytes = this.getBytes(length, forceClamped);
this.pos -= bytes.length;
return bytes;
},

28
src/core/stream.js
View File

@ -56,30 +56,33 @@ var Stream = (function StreamClosure() {
var b3 = this.getByte();
return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
},
// returns subarray of original buffer
// should only be read
getBytes: function Stream_getBytes(length) {
// Returns subarray of original buffer, should only be read.
getBytes(length, forceClamped = false) {
var bytes = this.bytes;
var pos = this.pos;
var strEnd = this.end;
if (!length) {
return bytes.subarray(pos, strEnd);
let subarray = bytes.subarray(pos, strEnd);
// `this.bytes` is always a `Uint8Array` here.
return (forceClamped ? new Uint8ClampedArray(subarray) : subarray);
}
var end = pos + length;
if (end > strEnd) {
end = strEnd;
}
this.pos = end;
return bytes.subarray(pos, end);
let subarray = bytes.subarray(pos, end);
// `this.bytes` is always a `Uint8Array` here.
return (forceClamped ? new Uint8ClampedArray(subarray) : subarray);
},
peekByte: function Stream_peekByte() {
var peekedByte = this.getByte();
this.pos--;
return peekedByte;
},
peekBytes: function Stream_peekBytes(length) {
var bytes = this.getBytes(length);
peekBytes(length, forceClamped = false) {
var bytes = this.getBytes(length, forceClamped);
this.pos -= bytes.length;
return bytes;
},
@ -181,7 +184,7 @@ var DecodeStream = (function DecodeStreamClosure() {
var b3 = this.getByte();
return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
},
getBytes: function DecodeStream_getBytes(length) {
getBytes(length, forceClamped = false) {
var end, pos = this.pos;
if (length) {
@ -203,15 +206,18 @@ var DecodeStream = (function DecodeStreamClosure() {
}
this.pos = end;
return this.buffer.subarray(pos, end);
let subarray = this.buffer.subarray(pos, end);
// `this.buffer` is either a `Uint8Array` or `Uint8ClampedArray` here.
return (forceClamped && !(subarray instanceof Uint8ClampedArray) ?
new Uint8ClampedArray(subarray) : subarray);
},
peekByte: function DecodeStream_peekByte() {
var peekedByte = this.getByte();
this.pos--;
return peekedByte;
},
peekBytes: function DecodeStream_peekBytes(length) {
var bytes = this.getBytes(length);
peekBytes(length, forceClamped = false) {
var bytes = this.getBytes(length, forceClamped);
this.pos -= bytes.length;
return bytes;
},

5
test/unit/stream_spec.js
View File

@ -59,6 +59,11 @@ describe('stream', function() {
expect(result).toMatchTypedArray(
new Uint8Array([100, 3, 101, 2, 102, 1])
);
predictor.reset();
let clampedResult = predictor.getBytes(6, /* forceClamped = */ true);
expect(clampedResult).toEqual(
new Uint8ClampedArray([100, 3, 101, 2, 102, 1]));
});
});
});