v86/src/browser/lib.js

755 lines
20 KiB
JavaScript

"use strict";
/** @const */
var ASYNC_SAFE = false;
(function()
{
if(typeof XMLHttpRequest === "undefined")
{
v86util.load_file = load_file_nodejs;
}
else
{
v86util.load_file = load_file;
}
v86util.AsyncXHRBuffer = AsyncXHRBuffer;
v86util.AsyncXHRPartfileBuffer = AsyncXHRPartfileBuffer;
v86util.AsyncFileBuffer = AsyncFileBuffer;
v86util.SyncFileBuffer = SyncFileBuffer;
// Reads len characters at offset from Memory object mem as a JS string
v86util.read_sized_string_from_mem = function read_sized_string_from_mem(mem, offset, len)
{
offset >>>= 0;
len >>>= 0;
return String.fromCharCode(...new Uint8Array(mem.buffer, offset, len));
};
/**
* @param {string} filename
* @param {Object} options
*/
function load_file(filename, options)
{
var http = new XMLHttpRequest();
http.open(options.method || "get", filename, true);
if(options.as_json)
{
http.responseType = "json";
}
else
{
http.responseType = "arraybuffer";
}
if(options.headers)
{
var header_names = Object.keys(options.headers);
for(var i = 0; i < header_names.length; i++)
{
var name = header_names[i];
http.setRequestHeader(name, options.headers[name]);
}
}
if(options.range)
{
let start = options.range.start;
let end = start + options.range.length - 1;
http.setRequestHeader("Range", "bytes=" + start + "-" + end);
// Abort if server responds with complete file in response to range
// request, to prevent downloading large files from broken http servers
http.onreadystatechange = function()
{
if(http.status === 200)
{
http.abort();
}
};
}
http.onload = function(e)
{
if(http.readyState === 4)
{
if(http.status !== 200 && http.status !== 206)
{
console.error("Loading the image `" + filename + "` failed (status %d)", http.status);
}
else if(http.response)
{
options.done && options.done(http.response, http);
}
}
};
if(options.progress)
{
http.onprogress = function(e)
{
options.progress(e);
};
}
http.send(null);
}
function load_file_nodejs(filename, options)
{
let fs = require("fs");
if(options.range)
{
dbg_assert(!options.as_json);
fs["open"](filename, "r", (err, fd) =>
{
if(err) throw err;
let length = options.range.length;
var buffer = Buffer.allocUnsafe(length);
fs["read"](fd, buffer, 0, length, options.range.start, (err, bytes_read) =>
{
if(err) throw err;
dbg_assert(bytes_read === length);
options.done && options.done(new Uint8Array(buffer));
fs["close"](fd, (err) => {
if(err) throw err;
});
});
});
}
else
{
var o = {
encoding: options.as_json ? "utf-8" : null,
};
fs["readFile"](filename, o, function(err, data)
{
if(err)
{
console.log("Could not read file:", filename, err);
}
else
{
var result = data;
if(options.as_json)
{
result = JSON.parse(result);
}
else
{
result = new Uint8Array(result).buffer;
}
options.done(result);
}
});
}
}
if(typeof XMLHttpRequest === "undefined")
{
var determine_size = function(path, cb)
{
require("fs")["stat"](path, (err, stats) =>
{
if(err)
{
cb(err);
}
else
{
cb(null, stats.size);
}
});
};
}
else
{
var determine_size = function(url, cb)
{
v86util.load_file(url, {
done: (buffer, http) =>
{
var header = http.getResponseHeader("Content-Range") || "";
var match = header.match(/\/(\d+)\s*$/);
if(match)
{
cb(null, +match[1]);
}
else
{
const error = "`Range: bytes=...` header not supported (Got `" + header + "`)";
cb(error);
}
},
headers: {
Range: "bytes=0-0",
}
});
};
}
/**
* Asynchronous access to ArrayBuffer, loading blocks lazily as needed,
* using the `Range: bytes=...` header
*
* @constructor
* @param {string} filename Name of the file to download
* @param {number|undefined} size
*/
function AsyncXHRBuffer(filename, size)
{
this.filename = filename;
/** @const */
this.block_size = 256;
this.byteLength = size;
this.loaded_blocks = Object.create(null);
this.onload = undefined;
this.onprogress = undefined;
}
AsyncXHRBuffer.prototype.load = function()
{
if(this.byteLength !== undefined)
{
this.onload && this.onload(Object.create(null));
return;
}
// Determine the size using a request
determine_size(this.filename, (error, size) =>
{
if(error)
{
console.assert(false, "Cannot use: " + this.filename + ". " + error);
}
else
{
dbg_assert(size >= 0);
this.byteLength = size;
this.onload && this.onload(Object.create(null));
}
});
};
/**
* @param {number} offset
* @param {number} len
* @param {function(!Uint8Array)} fn
*/
AsyncXHRBuffer.prototype.get_from_cache = function(offset, len, fn)
{
var number_of_blocks = len / this.block_size;
var block_index = offset / this.block_size;
for(var i = 0; i < number_of_blocks; i++)
{
var block = this.loaded_blocks[block_index + i];
if(!block)
{
return;
}
}
if(number_of_blocks === 1)
{
return this.loaded_blocks[block_index];
}
else
{
var result = new Uint8Array(len);
for(var i = 0; i < number_of_blocks; i++)
{
result.set(this.loaded_blocks[block_index + i], i * this.block_size);
}
return result;
}
};
/**
* @param {number} offset
* @param {number} len
* @param {function(!Uint8Array)} fn
*/
AsyncXHRBuffer.prototype.get = function(offset, len, fn)
{
console.assert(offset + len <= this.byteLength);
console.assert(offset % this.block_size === 0);
console.assert(len % this.block_size === 0);
console.assert(len);
var block = this.get_from_cache(offset, len, fn);
if(block)
{
if(ASYNC_SAFE)
{
setTimeout(fn.bind(this, block), 0);
}
else
{
fn(block);
}
return;
}
v86util.load_file(this.filename, {
done: function done(buffer)
{
var block = new Uint8Array(buffer);
this.handle_read(offset, len, block);
fn(block);
}.bind(this),
range: { start: offset, length: len },
});
};
/**
* Relies on this.byteLength, this.loaded_blocks and this.block_size
*
* @this {AsyncFileBuffer|AsyncXHRBuffer|AsyncXHRPartfileBuffer}
*
* @param {number} start
* @param {!Uint8Array} data
* @param {function()} fn
*/
AsyncXHRBuffer.prototype.set = function(start, data, fn)
{
console.assert(start + data.byteLength <= this.byteLength);
var len = data.length;
console.assert(start % this.block_size === 0);
console.assert(len % this.block_size === 0);
console.assert(len);
var start_block = start / this.block_size;
var block_count = len / this.block_size;
for(var i = 0; i < block_count; i++)
{
var block = this.loaded_blocks[start_block + i];
if(block === undefined)
{
block = this.loaded_blocks[start_block + i] = new Uint8Array(this.block_size);
}
var data_slice = data.subarray(i * this.block_size, (i + 1) * this.block_size);
block.set(data_slice);
console.assert(block.byteLength === data_slice.length);
}
fn();
};
/**
* @this {AsyncFileBuffer|AsyncXHRBuffer|AsyncXHRPartfileBuffer}
* @param {number} offset
* @param {number} len
* @param {!Uint8Array} block
*/
AsyncXHRBuffer.prototype.handle_read = function(offset, len, block)
{
// Used by AsyncXHRBuffer and AsyncFileBuffer
// Overwrites blocks from the original source that have been written since
var start_block = offset / this.block_size;
var block_count = len / this.block_size;
for(var i = 0; i < block_count; i++)
{
var written_block = this.loaded_blocks[start_block + i];
if(written_block)
{
block.set(written_block, i * this.block_size);
}
//else
//{
// var cached = this.loaded_blocks[start_block + i] = new Uint8Array(this.block_size);
// cached.set(block.subarray(i * this.block_size, (i + 1) * this.block_size));
//}
}
};
AsyncXHRBuffer.prototype.get_buffer = function(fn)
{
// We must download all parts, unlikely a good idea for big files
fn();
};
AsyncXHRBuffer.prototype.get_written_blocks = function()
{
var count = Object.keys(this.loaded_blocks).length;
var buffer = new Uint8Array(count * this.block_size);
var indices = [];
var i = 0;
for(var index of Object.keys(this.loaded_blocks))
{
var block = this.loaded_blocks[index];
dbg_assert(block.length === this.block_size);
index = +index;
indices.push(index);
buffer.set(
block,
i * this.block_size
);
i++;
}
return {
buffer,
indices,
block_size: this.block_size,
};
};
AsyncXHRBuffer.prototype.get_state = function()
{
const state = [];
const loaded_blocks = [];
for(let [index, block] of Object.entries(this.loaded_blocks))
{
dbg_assert(isFinite(+index));
loaded_blocks.push([+index, block]);
}
state[0] = loaded_blocks;
return state;
};
AsyncXHRBuffer.prototype.set_state = function(state)
{
const loaded_blocks = state[0];
this.loaded_blocks = Object.create(null);
for(let [index, block] of Object.values(loaded_blocks))
{
this.loaded_blocks[index] = block;
}
};
/**
* Asynchronous access to ArrayBuffer, loading blocks lazily as needed,
* downloading files named filename-\d-\d.ext.
*
* @constructor
* @param {string} filename Name of the file to download
* @param {number|undefined} size
*/
function AsyncXHRPartfileBuffer(filename, size)
{
const parts = filename.match(/(.*)(\..*)/);
if(parts)
{
this.basename = parts[1];
this.extension = parts[2];
}
else
{
this.basename = filename;
this.extension = "";
}
/** @const */
this.block_size = 256;
this.byteLength = size;
this.loaded_blocks = Object.create(null);
this.onload = undefined;
this.onprogress = undefined;
}
AsyncXHRPartfileBuffer.prototype.load = function()
{
if(this.byteLength !== undefined)
{
this.onload && this.onload(Object.create(null));
return;
}
dbg_assert(false);
this.onload && this.onload(Object.create(null));
};
AsyncXHRPartfileBuffer.prototype.get_from_cache = AsyncXHRBuffer.prototype.get_from_cache;
/**
* @param {number} offset
* @param {number} len
* @param {function(!Uint8Array)} fn
*/
AsyncXHRPartfileBuffer.prototype.get = function(offset, len, fn)
{
console.assert(offset + len <= this.byteLength);
console.assert(offset % this.block_size === 0);
console.assert(len % this.block_size === 0);
console.assert(len);
var block = this.get_from_cache(offset, len, fn);
if(block)
{
if(ASYNC_SAFE)
{
setTimeout(fn.bind(this, block), 0);
}
else
{
fn(block);
}
return;
}
const part_filename = this.basename + "-" + offset + "-" + (offset + len) + this.extension;
v86util.load_file(part_filename, {
done: function done(buffer)
{
dbg_assert(buffer.byteLength === len);
var block = new Uint8Array(buffer);
this.handle_read(offset, len, block);
fn(block);
}.bind(this),
});
};
AsyncXHRPartfileBuffer.prototype.set = AsyncXHRBuffer.prototype.set;
AsyncXHRPartfileBuffer.prototype.handle_read = AsyncXHRBuffer.prototype.handle_read;
AsyncXHRPartfileBuffer.prototype.get_written_blocks = AsyncXHRBuffer.prototype.get_written_blocks;
AsyncXHRPartfileBuffer.prototype.get_state = AsyncXHRBuffer.prototype.get_state;
AsyncXHRPartfileBuffer.prototype.set_state = AsyncXHRBuffer.prototype.set_state;
/**
* Synchronous access to File, loading blocks from the input type=file
* The whole file is loaded into memory during initialisation
*
* @constructor
*/
function SyncFileBuffer(file)
{
this.file = file;
this.byteLength = file.size;
if(file.size > (1 << 30))
{
console.warn("SyncFileBuffer: Allocating buffer of " + (file.size >> 20) + " MB ...");
}
this.buffer = new ArrayBuffer(file.size);
this.onload = undefined;
this.onprogress = undefined;
}
SyncFileBuffer.prototype.load = function()
{
this.load_next(0);
};
/**
* @param {number} start
*/
SyncFileBuffer.prototype.load_next = function(start)
{
/** @const */
var PART_SIZE = 4 << 20;
var filereader = new FileReader();
filereader.onload = function(e)
{
var buffer = new Uint8Array(e.target.result);
new Uint8Array(this.buffer, start).set(buffer);
this.load_next(start + PART_SIZE);
}.bind(this);
if(this.onprogress)
{
this.onprogress({
loaded: start,
total: this.byteLength,
lengthComputable: true,
});
}
if(start < this.byteLength)
{
var end = Math.min(start + PART_SIZE, this.byteLength);
var slice = this.file.slice(start, end);
filereader.readAsArrayBuffer(slice);
}
else
{
this.file = undefined;
this.onload && this.onload({ buffer: this.buffer });
}
};
/**
* @param {number} start
* @param {number} len
* @param {function(!Uint8Array)} fn
*/
SyncFileBuffer.prototype.get = function(start, len, fn)
{
console.assert(start + len <= this.byteLength);
fn(new Uint8Array(this.buffer, start, len));
};
/**
* @param {number} offset
* @param {!Uint8Array} slice
* @param {function()} fn
*/
SyncFileBuffer.prototype.set = function(offset, slice, fn)
{
console.assert(offset + slice.byteLength <= this.byteLength);
new Uint8Array(this.buffer, offset, slice.byteLength).set(slice);
fn();
};
SyncFileBuffer.prototype.get_buffer = function(fn)
{
fn(this.buffer);
};
SyncFileBuffer.prototype.get_state = function()
{
const state = [];
state[0] = this.byteLength;
state[1] = new Uint8Array(this.buffer);
return state;
};
SyncFileBuffer.prototype.set_state = function(state)
{
this.byteLength = state[0];
this.buffer = state[1].slice().buffer;
};
/**
* Asynchronous access to File, loading blocks from the input type=file
*
* @constructor
*/
function AsyncFileBuffer(file)
{
this.file = file;
this.byteLength = file.size;
/** @const */
this.block_size = 256;
this.loaded_blocks = Object.create(null);
this.onload = undefined;
this.onprogress = undefined;
}
AsyncFileBuffer.prototype.load = function()
{
this.onload && this.onload(Object.create(null));
};
/**
* @param {number} offset
* @param {number} len
* @param {function(!Uint8Array)} fn
*/
AsyncFileBuffer.prototype.get = function(offset, len, fn)
{
console.assert(offset % this.block_size === 0);
console.assert(len % this.block_size === 0);
console.assert(len);
var block = this.get_from_cache(offset, len, fn);
if(block)
{
fn(block);
return;
}
var fr = new FileReader();
fr.onload = function(e)
{
var buffer = e.target.result;
var block = new Uint8Array(buffer);
this.handle_read(offset, len, block);
fn(block);
}.bind(this);
fr.readAsArrayBuffer(this.file.slice(offset, offset + len));
};
AsyncFileBuffer.prototype.get_from_cache = AsyncXHRBuffer.prototype.get_from_cache;
AsyncFileBuffer.prototype.set = AsyncXHRBuffer.prototype.set;
AsyncFileBuffer.prototype.handle_read = AsyncXHRBuffer.prototype.handle_read;
AsyncFileBuffer.prototype.get_buffer = function(fn)
{
// We must load all parts, unlikely a good idea for big files
fn();
};
AsyncFileBuffer.prototype.get_as_file = function(name)
{
var parts = [];
var existing_blocks = Object.keys(this.loaded_blocks)
.map(Number)
.sort(function(x, y) { return x - y; });
var current_offset = 0;
for(var i = 0; i < existing_blocks.length; i++)
{
var block_index = existing_blocks[i];
var block = this.loaded_blocks[block_index];
var start = block_index * this.block_size;
console.assert(start >= current_offset);
if(start !== current_offset)
{
parts.push(this.file.slice(current_offset, start));
current_offset = start;
}
parts.push(block);
current_offset += block.length;
}
if(current_offset !== this.file.size)
{
parts.push(this.file.slice(current_offset));
}
var file = new File(parts, name);
console.assert(file.size === this.file.size);
return file;
};
})();