43 lines
1.1 KiB
JavaScript
43 lines
1.1 KiB
JavaScript
/* very simple input/output stream interface */
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var Stream = function() {
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};
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// input streams //////////////
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/** Returns the next byte, or -1 for EOF. */
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Stream.prototype.readByte = function() {
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throw new Error("abstract method readByte() not implemented");
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};
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/** Attempts to fill the buffer; returns number of bytes read, or
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* -1 for EOF. */
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Stream.prototype.read = function(buffer, bufOffset, length) {
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var bytesRead = 0;
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while (bytesRead < length) {
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var c = this.readByte();
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if (c < 0) { // EOF
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return (bytesRead===0) ? -1 : bytesRead;
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}
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buffer[bufOffset++] = c;
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bytesRead++;
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}
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return bytesRead;
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};
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Stream.prototype.seek = function(new_pos) {
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throw new Error("abstract method seek() not implemented");
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};
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// output streams ///////////
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Stream.prototype.writeByte = function(_byte) {
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throw new Error("abstract method readByte() not implemented");
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};
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Stream.prototype.write = function(buffer, bufOffset, length) {
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var i;
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for (i=0; i<length; i++) {
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this.writeByte(buffer[bufOffset++]);
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}
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return length;
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};
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Stream.prototype.flush = function() {
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};
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module.exports = Stream;
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