diff options
author | Ryan Dahl <ry@tinyclouds.org> | 2020-07-23 10:27:26 -0400 |
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committer | GitHub <noreply@github.com> | 2020-07-23 16:27:26 +0200 |
commit | ca4dcb36dd5be0b14a2fafa059ea02ee7e0a0262 (patch) | |
tree | 393fc85f19e97bb66402676f67e63690d7a29e00 /cli/rt/20_blob.js | |
parent | 090455936c892b6f2dfa425be9b1cdfb4c63af4a (diff) |
Rename cli/js2 to cli/rt (#6857)
Diffstat (limited to 'cli/rt/20_blob.js')
-rw-r--r-- | cli/rt/20_blob.js | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/cli/rt/20_blob.js b/cli/rt/20_blob.js new file mode 100644 index 000000000..5b0ef349e --- /dev/null +++ b/cli/rt/20_blob.js @@ -0,0 +1,223 @@ +// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license. + +((window) => { + const { build } = window.__bootstrap.build; + const { ReadableStream } = window.__bootstrap.streams; + + const bytesSymbol = Symbol("bytes"); + + function containsOnlyASCII(str) { + if (typeof str !== "string") { + return false; + } + return /^[\x00-\x7F]*$/.test(str); + } + + function convertLineEndingsToNative(s) { + const nativeLineEnd = build.os == "windows" ? "\r\n" : "\n"; + + let position = 0; + + let collectionResult = collectSequenceNotCRLF(s, position); + + let token = collectionResult.collected; + position = collectionResult.newPosition; + + let result = token; + + while (position < s.length) { + const c = s.charAt(position); + if (c == "\r") { + result += nativeLineEnd; + position++; + if (position < s.length && s.charAt(position) == "\n") { + position++; + } + } else if (c == "\n") { + position++; + result += nativeLineEnd; + } + + collectionResult = collectSequenceNotCRLF(s, position); + + token = collectionResult.collected; + position = collectionResult.newPosition; + + result += token; + } + + return result; + } + + function collectSequenceNotCRLF( + s, + position, + ) { + const start = position; + for ( + let c = s.charAt(position); + position < s.length && !(c == "\r" || c == "\n"); + c = s.charAt(++position) + ); + return { collected: s.slice(start, position), newPosition: position }; + } + + function toUint8Arrays( + blobParts, + doNormalizeLineEndingsToNative, + ) { + const ret = []; + const enc = new TextEncoder(); + for (const element of blobParts) { + if (typeof element === "string") { + let str = element; + if (doNormalizeLineEndingsToNative) { + str = convertLineEndingsToNative(element); + } + ret.push(enc.encode(str)); + // eslint-disable-next-line @typescript-eslint/no-use-before-define + } else if (element instanceof Blob) { + ret.push(element[bytesSymbol]); + } else if (element instanceof Uint8Array) { + ret.push(element); + } else if (element instanceof Uint16Array) { + const uint8 = new Uint8Array(element.buffer); + ret.push(uint8); + } else if (element instanceof Uint32Array) { + const uint8 = new Uint8Array(element.buffer); + ret.push(uint8); + } else if (ArrayBuffer.isView(element)) { + // Convert view to Uint8Array. + const uint8 = new Uint8Array(element.buffer); + ret.push(uint8); + } else if (element instanceof ArrayBuffer) { + // Create a new Uint8Array view for the given ArrayBuffer. + const uint8 = new Uint8Array(element); + ret.push(uint8); + } else { + ret.push(enc.encode(String(element))); + } + } + return ret; + } + + function processBlobParts( + blobParts, + options, + ) { + const normalizeLineEndingsToNative = options.ending === "native"; + // ArrayBuffer.transfer is not yet implemented in V8, so we just have to + // pre compute size of the array buffer and do some sort of static allocation + // instead of dynamic allocation. + const uint8Arrays = toUint8Arrays(blobParts, normalizeLineEndingsToNative); + const byteLength = uint8Arrays + .map((u8) => u8.byteLength) + .reduce((a, b) => a + b, 0); + const ab = new ArrayBuffer(byteLength); + const bytes = new Uint8Array(ab); + let courser = 0; + for (const u8 of uint8Arrays) { + bytes.set(u8, courser); + courser += u8.byteLength; + } + + return bytes; + } + + function getStream(blobBytes) { + // TODO: Align to spec https://fetch.spec.whatwg.org/#concept-construct-readablestream + return new ReadableStream({ + type: "bytes", + start: (controller) => { + controller.enqueue(blobBytes); + controller.close(); + }, + }); + } + + async function readBytes( + reader, + ) { + const chunks = []; + while (true) { + const { done, value } = await reader.read(); + if (!done && value instanceof Uint8Array) { + chunks.push(value); + } else if (done) { + const size = chunks.reduce((p, i) => p + i.byteLength, 0); + const bytes = new Uint8Array(size); + let offs = 0; + for (const chunk of chunks) { + bytes.set(chunk, offs); + offs += chunk.byteLength; + } + return bytes; + } else { + throw new TypeError("Invalid reader result."); + } + } + } + + // A WeakMap holding blob to byte array mapping. + // Ensures it does not impact garbage collection. + const blobBytesWeakMap = new WeakMap(); + + class Blob { + constructor(blobParts, options) { + if (arguments.length === 0) { + this[bytesSymbol] = new Uint8Array(); + return; + } + + const { ending = "transparent", type = "" } = options ?? {}; + // Normalize options.type. + let normalizedType = type; + if (!containsOnlyASCII(type)) { + normalizedType = ""; + } else { + if (type.length) { + for (let i = 0; i < type.length; ++i) { + const char = type[i]; + if (char < "\u0020" || char > "\u007E") { + normalizedType = ""; + break; + } + } + normalizedType = type.toLowerCase(); + } + } + const bytes = processBlobParts(blobParts, { ending, type }); + // Set Blob object's properties. + this[bytesSymbol] = bytes; + this.size = bytes.byteLength; + this.type = normalizedType; + } + + slice(start, end, contentType) { + return new Blob([this[bytesSymbol].slice(start, end)], { + type: contentType || this.type, + }); + } + + stream() { + return getStream(this[bytesSymbol]); + } + + async text() { + const reader = getStream(this[bytesSymbol]).getReader(); + const decoder = new TextDecoder(); + return decoder.decode(await readBytes(reader)); + } + + arrayBuffer() { + return readBytes(getStream(this[bytesSymbol]).getReader()); + } + } + + window.__bootstrap.blob = { + Blob, + bytesSymbol, + containsOnlyASCII, + blobBytesWeakMap, + }; +})(this); |