749 lines
22 KiB
JavaScript
749 lines
22 KiB
JavaScript
"use strict";
|
|
|
|
(function()
|
|
{
|
|
v86util.SyncBuffer = SyncBuffer;
|
|
v86util.AsyncXHRBuffer = AsyncXHRBuffer;
|
|
v86util.AsyncXHRPartfileBuffer = AsyncXHRPartfileBuffer;
|
|
v86util.AsyncFileBuffer = AsyncFileBuffer;
|
|
v86util.SyncFileBuffer = SyncFileBuffer;
|
|
|
|
// The smallest size the emulated hardware can emit
|
|
const BLOCK_SIZE = 256;
|
|
|
|
const ASYNC_SAFE = false;
|
|
|
|
/**
|
|
* Synchronous access to ArrayBuffer
|
|
* @constructor
|
|
*/
|
|
function SyncBuffer(buffer)
|
|
{
|
|
dbg_assert(buffer instanceof ArrayBuffer);
|
|
|
|
this.buffer = buffer;
|
|
this.byteLength = buffer.byteLength;
|
|
this.onload = undefined;
|
|
this.onprogress = undefined;
|
|
}
|
|
|
|
SyncBuffer.prototype.load = function()
|
|
{
|
|
this.onload && this.onload({ buffer: this.buffer });
|
|
};
|
|
|
|
/**
|
|
* @this {SyncBuffer|SyncFileBuffer}
|
|
* @param {number} start
|
|
* @param {number} len
|
|
* @param {function(!Uint8Array)} fn
|
|
*/
|
|
SyncBuffer.prototype.get = function(start, len, fn)
|
|
{
|
|
dbg_assert(start + len <= this.byteLength);
|
|
fn(new Uint8Array(this.buffer, start, len));
|
|
};
|
|
|
|
/**
|
|
* @this {SyncBuffer|SyncFileBuffer}
|
|
* @param {number} start
|
|
* @param {!Uint8Array} slice
|
|
* @param {function()} fn
|
|
*/
|
|
SyncBuffer.prototype.set = function(start, slice, fn)
|
|
{
|
|
dbg_assert(start + slice.byteLength <= this.byteLength);
|
|
|
|
new Uint8Array(this.buffer, start, slice.byteLength).set(slice);
|
|
fn();
|
|
};
|
|
|
|
/**
|
|
* @this {SyncBuffer|SyncFileBuffer}
|
|
* @param {function(!ArrayBuffer)} fn
|
|
*/
|
|
SyncBuffer.prototype.get_buffer = function(fn)
|
|
{
|
|
fn(this.buffer);
|
|
};
|
|
|
|
/**
|
|
* @this {SyncBuffer|SyncFileBuffer}
|
|
*/
|
|
SyncBuffer.prototype.get_state = function()
|
|
{
|
|
const state = [];
|
|
state[0] = this.byteLength;
|
|
state[1] = new Uint8Array(this.buffer);
|
|
return state;
|
|
};
|
|
|
|
/**
|
|
* @this {SyncBuffer|SyncFileBuffer}
|
|
*/
|
|
SyncBuffer.prototype.set_state = function(state)
|
|
{
|
|
this.byteLength = state[0];
|
|
this.buffer = state[1].slice().buffer;
|
|
};
|
|
|
|
/**
|
|
* 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
|
|
* @param {number|undefined} fixed_chunk_size
|
|
*/
|
|
function AsyncXHRBuffer(filename, size, fixed_chunk_size)
|
|
{
|
|
this.filename = filename;
|
|
|
|
this.byteLength = size;
|
|
|
|
this.block_cache = new Map();
|
|
this.block_cache_is_write = new Set();
|
|
|
|
this.fixed_chunk_size = fixed_chunk_size;
|
|
this.cache_reads = !!fixed_chunk_size; // TODO: could also be useful in other cases (needs testing)
|
|
|
|
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)
|
|
{
|
|
throw new Error("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
|
|
* @this {AsyncXHRBuffer|AsyncXHRPartfileBuffer|AsyncFileBuffer}
|
|
*/
|
|
AsyncXHRBuffer.prototype.get_from_cache = function(offset, len)
|
|
{
|
|
var number_of_blocks = len / BLOCK_SIZE;
|
|
var block_index = offset / BLOCK_SIZE;
|
|
|
|
for(var i = 0; i < number_of_blocks; i++)
|
|
{
|
|
var block = this.block_cache.get(block_index + i);
|
|
|
|
if(!block)
|
|
{
|
|
return;
|
|
}
|
|
}
|
|
|
|
if(number_of_blocks === 1)
|
|
{
|
|
return this.block_cache.get(block_index);
|
|
}
|
|
else
|
|
{
|
|
var result = new Uint8Array(len);
|
|
for(var i = 0; i < number_of_blocks; i++)
|
|
{
|
|
result.set(this.block_cache.get(block_index + i), i * BLOCK_SIZE);
|
|
}
|
|
return result;
|
|
}
|
|
};
|
|
|
|
/**
|
|
* @param {number} offset
|
|
* @param {number} len
|
|
* @param {function(!Uint8Array)} fn
|
|
*/
|
|
AsyncXHRBuffer.prototype.get = function(offset, len, fn)
|
|
{
|
|
dbg_assert(offset + len <= this.byteLength);
|
|
dbg_assert(offset % BLOCK_SIZE === 0);
|
|
dbg_assert(len % BLOCK_SIZE === 0);
|
|
dbg_assert(len);
|
|
|
|
var block = this.get_from_cache(offset, len);
|
|
if(block)
|
|
{
|
|
if(ASYNC_SAFE)
|
|
{
|
|
setTimeout(fn.bind(this, block), 0);
|
|
}
|
|
else
|
|
{
|
|
fn(block);
|
|
}
|
|
return;
|
|
}
|
|
|
|
var requested_start = offset;
|
|
var requested_length = len;
|
|
if(this.fixed_chunk_size)
|
|
{
|
|
requested_start = offset - (offset % this.fixed_chunk_size);
|
|
requested_length = Math.ceil((offset - requested_start + len) / this.fixed_chunk_size) * this.fixed_chunk_size;
|
|
}
|
|
|
|
v86util.load_file(this.filename, {
|
|
done: function done(buffer)
|
|
{
|
|
var block = new Uint8Array(buffer);
|
|
this.handle_read(requested_start, requested_length, block);
|
|
if(requested_start === offset && requested_length === len)
|
|
{
|
|
fn(block);
|
|
}
|
|
else
|
|
{
|
|
fn(block.subarray(offset - requested_start, offset - requested_start + len));
|
|
}
|
|
}.bind(this),
|
|
range: { start: requested_start, length: requested_length },
|
|
});
|
|
};
|
|
|
|
/**
|
|
* Relies on this.byteLength and this.block_cache
|
|
*
|
|
* @this {AsyncXHRBuffer|AsyncXHRPartfileBuffer|AsyncFileBuffer}
|
|
*
|
|
* @param {number} start
|
|
* @param {!Uint8Array} data
|
|
* @param {function()} fn
|
|
*/
|
|
AsyncXHRBuffer.prototype.set = function(start, data, fn)
|
|
{
|
|
var len = data.length;
|
|
dbg_assert(start + data.byteLength <= this.byteLength);
|
|
dbg_assert(start % BLOCK_SIZE === 0);
|
|
dbg_assert(len % BLOCK_SIZE === 0);
|
|
dbg_assert(len);
|
|
|
|
var start_block = start / BLOCK_SIZE;
|
|
var block_count = len / BLOCK_SIZE;
|
|
|
|
for(var i = 0; i < block_count; i++)
|
|
{
|
|
var block = this.block_cache.get(start_block + i);
|
|
|
|
if(block === undefined)
|
|
{
|
|
const data_slice = data.slice(i * BLOCK_SIZE, (i + 1) * BLOCK_SIZE);
|
|
this.block_cache.set(start_block + i, data_slice);
|
|
}
|
|
else
|
|
{
|
|
const data_slice = data.subarray(i * BLOCK_SIZE, (i + 1) * BLOCK_SIZE);
|
|
dbg_assert(block.byteLength === data_slice.length);
|
|
block.set(data_slice);
|
|
}
|
|
|
|
this.block_cache_is_write.add(start_block + i);
|
|
}
|
|
|
|
fn();
|
|
};
|
|
|
|
/**
|
|
* @this {AsyncXHRBuffer|AsyncXHRPartfileBuffer|AsyncFileBuffer}
|
|
* @param {number} offset
|
|
* @param {number} len
|
|
* @param {!Uint8Array} block
|
|
*/
|
|
AsyncXHRBuffer.prototype.handle_read = function(offset, len, block)
|
|
{
|
|
// Used by AsyncXHRBuffer, AsyncXHRPartfileBuffer and AsyncFileBuffer
|
|
// Overwrites blocks from the original source that have been written since
|
|
|
|
var start_block = offset / BLOCK_SIZE;
|
|
var block_count = len / BLOCK_SIZE;
|
|
|
|
for(var i = 0; i < block_count; i++)
|
|
{
|
|
const cached_block = this.block_cache.get(start_block + i);
|
|
|
|
if(cached_block)
|
|
{
|
|
block.set(cached_block, i * BLOCK_SIZE);
|
|
}
|
|
else if(this.cache_reads)
|
|
{
|
|
this.block_cache.set(start_block + i, block.slice(i * BLOCK_SIZE, (i + 1) * BLOCK_SIZE));
|
|
}
|
|
}
|
|
};
|
|
|
|
AsyncXHRBuffer.prototype.get_buffer = function(fn)
|
|
{
|
|
// We must download all parts, unlikely a good idea for big files
|
|
fn();
|
|
};
|
|
|
|
///**
|
|
// * @this {AsyncXHRBuffer|AsyncXHRPartfileBuffer|AsyncFileBuffer}
|
|
// */
|
|
//AsyncXHRBuffer.prototype.get_block_cache = function()
|
|
//{
|
|
// var count = Object.keys(this.block_cache).length;
|
|
|
|
// var buffer = new Uint8Array(count * BLOCK_SIZE);
|
|
// var indices = [];
|
|
|
|
// var i = 0;
|
|
// for(var index of Object.keys(this.block_cache))
|
|
// {
|
|
// var block = this.block_cache.get(index);
|
|
// dbg_assert(block.length === BLOCK_SIZE);
|
|
// index = +index;
|
|
// indices.push(index);
|
|
// buffer.set(
|
|
// block,
|
|
// i * BLOCK_SIZE
|
|
// );
|
|
// i++;
|
|
// }
|
|
|
|
// return {
|
|
// buffer,
|
|
// indices,
|
|
// block_size: BLOCK_SIZE,
|
|
// };
|
|
//};
|
|
|
|
/**
|
|
* @this {AsyncXHRBuffer|AsyncXHRPartfileBuffer|AsyncFileBuffer}
|
|
*/
|
|
AsyncXHRBuffer.prototype.get_state = function()
|
|
{
|
|
const state = [];
|
|
const block_cache = [];
|
|
|
|
for(let [index, block] of this.block_cache)
|
|
{
|
|
dbg_assert(isFinite(index));
|
|
if(this.block_cache_is_write.has(index))
|
|
{
|
|
block_cache.push([index, block]);
|
|
}
|
|
}
|
|
|
|
state[0] = block_cache;
|
|
return state;
|
|
};
|
|
|
|
/**
|
|
* @this {AsyncXHRBuffer|AsyncXHRPartfileBuffer|AsyncFileBuffer}
|
|
*/
|
|
AsyncXHRBuffer.prototype.set_state = function(state)
|
|
{
|
|
const block_cache = state[0];
|
|
this.block_cache.clear();
|
|
this.block_cache_is_write.clear();
|
|
|
|
for(let [index, block] of block_cache)
|
|
{
|
|
dbg_assert(isFinite(index));
|
|
this.block_cache.set(index, block);
|
|
this.block_cache_is_write.add(index);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Asynchronous access to ArrayBuffer, loading blocks lazily as needed,
|
|
* downloading files named filename-%d-%d.ext (where the %d are start and end offset).
|
|
* Or, if partfile_alt_format is set, filename-%08d.ext (where %d is the part number, compatible with gnu split).
|
|
*
|
|
* @constructor
|
|
* @param {string} filename Name of the file to download
|
|
* @param {number|undefined} size
|
|
* @param {number|undefined} fixed_chunk_size
|
|
* @param {boolean|undefined} partfile_alt_format
|
|
*/
|
|
function AsyncXHRPartfileBuffer(filename, size, fixed_chunk_size, partfile_alt_format)
|
|
{
|
|
const parts = filename.match(/(.*)(\..*)/);
|
|
|
|
if(parts)
|
|
{
|
|
this.basename = parts[1];
|
|
this.extension = parts[2];
|
|
}
|
|
else
|
|
{
|
|
this.basename = filename;
|
|
this.extension = "";
|
|
}
|
|
|
|
if(!this.basename.endsWith("/"))
|
|
{
|
|
this.basename += "-";
|
|
}
|
|
|
|
this.block_cache = new Map();
|
|
this.block_cache_is_write = new Set();
|
|
|
|
this.byteLength = size;
|
|
this.fixed_chunk_size = fixed_chunk_size;
|
|
this.partfile_alt_format = !!partfile_alt_format;
|
|
|
|
this.cache_reads = !!fixed_chunk_size; // TODO: could also be useful in other cases (needs testing)
|
|
|
|
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));
|
|
};
|
|
|
|
/**
|
|
* @param {number} offset
|
|
* @param {number} len
|
|
* @param {function(!Uint8Array)} fn
|
|
*/
|
|
AsyncXHRPartfileBuffer.prototype.get = function(offset, len, fn)
|
|
{
|
|
dbg_assert(offset + len <= this.byteLength);
|
|
dbg_assert(offset % BLOCK_SIZE === 0);
|
|
dbg_assert(len % BLOCK_SIZE === 0);
|
|
dbg_assert(len);
|
|
|
|
const block = this.get_from_cache(offset, len);
|
|
|
|
if(block)
|
|
{
|
|
if(ASYNC_SAFE)
|
|
{
|
|
setTimeout(fn.bind(this, block), 0);
|
|
}
|
|
else
|
|
{
|
|
fn(block);
|
|
}
|
|
return;
|
|
}
|
|
|
|
if(this.fixed_chunk_size)
|
|
{
|
|
const start_index = Math.floor(offset / this.fixed_chunk_size);
|
|
const m_offset = offset - start_index * this.fixed_chunk_size;
|
|
dbg_assert(m_offset >= 0);
|
|
const total_count = Math.ceil((m_offset + len) / this.fixed_chunk_size);
|
|
const blocks = new Uint8Array(total_count * this.fixed_chunk_size);
|
|
let finished = 0;
|
|
|
|
for(let i = 0; i < total_count; i++)
|
|
{
|
|
const offset = (start_index + i) * this.fixed_chunk_size;
|
|
|
|
const part_filename =
|
|
this.partfile_alt_format ?
|
|
// matches output of gnu split:
|
|
// split -b 512 -a8 -d --additional-suffix .img w95.img w95-
|
|
this.basename + (start_index + i + "").padStart(8, "0") + this.extension
|
|
:
|
|
this.basename + offset + "-" + (offset + this.fixed_chunk_size) + this.extension;
|
|
|
|
// XXX: unnecessary allocation
|
|
const block = this.get_from_cache(offset, this.fixed_chunk_size);
|
|
|
|
if(block)
|
|
{
|
|
const cur = i * this.fixed_chunk_size;
|
|
blocks.set(block, cur);
|
|
finished++;
|
|
if(finished === total_count)
|
|
{
|
|
const tmp_blocks = blocks.subarray(m_offset, m_offset + len);
|
|
fn(tmp_blocks);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
v86util.load_file(part_filename, {
|
|
done: function done(buffer)
|
|
{
|
|
const cur = i * this.fixed_chunk_size;
|
|
const block = new Uint8Array(buffer);
|
|
this.handle_read((start_index + i) * this.fixed_chunk_size, this.fixed_chunk_size|0, block);
|
|
blocks.set(block, cur);
|
|
finished++;
|
|
if(finished === total_count)
|
|
{
|
|
const tmp_blocks = blocks.subarray(m_offset, m_offset + len);
|
|
fn(tmp_blocks);
|
|
}
|
|
}.bind(this),
|
|
});
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
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.get_from_cache = AsyncXHRBuffer.prototype.get_from_cache;
|
|
AsyncXHRPartfileBuffer.prototype.set = AsyncXHRBuffer.prototype.set;
|
|
AsyncXHRPartfileBuffer.prototype.handle_read = AsyncXHRBuffer.prototype.handle_read;
|
|
//AsyncXHRPartfileBuffer.prototype.get_block_cache = AsyncXHRBuffer.prototype.get_block_cache;
|
|
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 });
|
|
}
|
|
};
|
|
|
|
SyncFileBuffer.prototype.get = SyncBuffer.prototype.get;
|
|
SyncFileBuffer.prototype.set = SyncBuffer.prototype.set;
|
|
SyncFileBuffer.prototype.get_buffer = SyncBuffer.prototype.get_buffer;
|
|
SyncFileBuffer.prototype.get_state = SyncBuffer.prototype.get_state;
|
|
SyncFileBuffer.prototype.set_state = SyncBuffer.prototype.set_state;
|
|
|
|
/**
|
|
* Asynchronous access to File, loading blocks from the input type=file
|
|
*
|
|
* @constructor
|
|
*/
|
|
function AsyncFileBuffer(file)
|
|
{
|
|
this.file = file;
|
|
this.byteLength = file.size;
|
|
|
|
this.block_cache = new Map();
|
|
this.block_cache_is_write = new Set();
|
|
|
|
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)
|
|
{
|
|
dbg_assert(offset % BLOCK_SIZE === 0);
|
|
dbg_assert(len % BLOCK_SIZE === 0);
|
|
dbg_assert(len);
|
|
|
|
var block = this.get_from_cache(offset, len);
|
|
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_state = AsyncXHRBuffer.prototype.get_state;
|
|
AsyncFileBuffer.prototype.set_state = AsyncXHRBuffer.prototype.set_state;
|
|
|
|
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 = Array.from(this.block_cache.keys()).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.block_cache.get(block_index);
|
|
var start = block_index * BLOCK_SIZE;
|
|
dbg_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);
|
|
dbg_assert(file.size === this.file.size);
|
|
|
|
return file;
|
|
};
|
|
|
|
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",
|
|
}
|
|
});
|
|
};
|
|
}
|
|
})();
|