implement truncate and ftruncate

This commit is contained in:
Abir Viqar 2013-12-10 11:59:44 -05:00
parent 2c872fd354
commit 13abcd2eeb
4 changed files with 429 additions and 6 deletions

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@ -328,3 +328,11 @@ Asynchronous readlink(2). Callback gets `(error, linkContents)`, where `linkCont
#### fs.lstat(path, callback)
Asynchronous lstat(2). Callback gets `(error, stats)`, See `fs.stat`.
#### fs.truncate(path, length, callback)
Asynchronous truncate(2). Callback gets no additional arguments.
#### fs.ftruncate(fd, length, callback)
Asynchronous ftruncate(2). Callback gets no additional arguments.

148
src/fs.js
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@ -943,6 +943,96 @@ define(function(require) {
}
}
function truncate_file(context, path, length, callback) {
path = normalize(path);
var fileNode;
function read_file_data (error, node) {
if (error) {
callback(error);
} else if(node.mode == MODE_DIRECTORY ) {
callback(new EIsDirectory('the named file is a directory'));
} else{
fileNode = node;
context.get(fileNode.data, truncate_file_data);
}
}
function truncate_file_data(error, fileData) {
if (error) {
callback(error);
} else {
var data = new Uint8Array(length);
if(fileData) {
data.set(fileData.subarray(0, length));
}
context.put(fileNode.data, data, update_file_node);
}
}
function update_file_node (error) {
if(error) {
callback(error);
} else {
fileNode.size = length;
fileNode.mtime = Date.now();
fileNode.version += 1;
context.put(fileNode.id, fileNode, callback);
}
}
if(length < 0) {
callback(new EInvalid('length cannot be negative'));
} else {
find_node(context, path, read_file_data);
}
}
function ftruncate_file(context, ofd, length, callback) {
var fileNode;
function read_file_data (error, node) {
if (error) {
callback(error);
} else if(node.mode == MODE_DIRECTORY ) {
callback(new EIsDirectory('the named file is a directory'));
} else{
fileNode = node;
context.get(fileNode.data, truncate_file_data);
}
}
function truncate_file_data(error, fileData) {
if (error) {
callback(error);
} else {
var data = new Uint8Array(length);
if(fileData) {
data.set(fileData.subarray(0, length));
}
context.put(fileNode.data, data, update_file_node);
}
}
function update_file_node (error) {
if(error) {
callback(error);
} else {
fileNode.size = length;
fileNode.mtime = Date.now();
fileNode.version += 1;
context.put(fileNode.id, fileNode, callback);
}
}
if(length < 0) {
callback(new EInvalid('length cannot be negative'));
} else {
context.get(ofd.id, read_file_data);
}
}
function validate_flags(flags) {
if(!_(O_FLAGS).has(flags)) {
return null;
@ -1505,14 +1595,38 @@ define(function(require) {
lstat_file(context, path, check_result);
}
function _truncate(path, length, callback) {
// TODO
// if(!nullCheck(path, callback)) return;
function _truncate(context, path, length, callback) {
if(!nullCheck(path, callback)) return;
function check_result(error) {
if(error) {
callback(error);
} else {
callback(null);
}
}
function _ftruncate(fd, length, callback) {
// TODO
// if(!nullCheck(path, callback)) return;
truncate_file(context, path, length, check_result);
}
function _ftruncate(fs, context, fd, length, callback) {
function check_result(error) {
if(error) {
callback(error);
} else {
callback(null);
}
}
var ofd = fs.openFiles[fd];
if(!ofd) {
callback(new EBadFileDescriptor('invalid file descriptor'));
} else if(!_(ofd.flags).contains(O_WRITE)) {
callback(new EBadFileDescriptor('descriptor does not permit writing'));
} else {
ftruncate_file(context, ofd, length, check_result);
}
}
@ -1723,6 +1837,28 @@ define(function(require) {
);
if(error) callback(error);
};
FileSystem.prototype.truncate = function(path, length, callback) {
callback = maybeCallback(callback);
var fs = this;
var error = fs.queueOrRun(
function() {
var context = fs.provider.getReadWriteContext();
_truncate(context, path, length, callback);
}
);
if(error) callback(error);
};
FileSystem.prototype.ftruncate = function(fd, length, callback) {
callback = maybeCallback(callback);
var fs = this;
var error = fs.queueOrRun(
function() {
var context = fs.provider.getReadWriteContext();
_ftruncate(fs, context, fd, length, callback);
}
);
if(error) callback(error);
};
return {
FileSystem: FileSystem,

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@ -0,0 +1,278 @@
define(["IDBFS"], function(IDBFS) {
describe('fs.truncate', function() {
beforeEach(function() {
this.db_name = mk_db_name();
this.fs = new IDBFS.FileSystem({
name: this.db_name,
flags: 'FORMAT'
});
});
afterEach(function() {
indexedDB.deleteDatabase(this.db_name);
delete this.fs;
});
it('should be a function', function() {
expect(typeof this.fs.truncate).toEqual('function');
});
it('should error when length is negative', function() {
var complete = false;
var _error, _result;
var that = this;
var contents = "This is a file.";
that.fs.writeFile('/myfile', contents, function(error) {
if(error) throw error;
that.fs.truncate('/myfile', -1, function(error) {
_error = error;
complete = true;
});
});
waitsFor(function() {
return complete;
}, 'test to complete', DEFAULT_TIMEOUT);
runs(function() {
expect(_error).toBeDefined();
});
});
it('should error when path is not a file', function() {
var complete = false;
var _error, _result;
var that = this;
that.fs.truncate('/', 0, function(error) {
_error = error;
complete = true;
});
waitsFor(function() {
return complete;
}, 'test to complete', DEFAULT_TIMEOUT);
runs(function() {
expect(_error).toBeDefined();
});
});
it('should truncate a file', function() {
var complete = false;
var _error, _result;
var that = this;
var buffer = new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8]);
var truncated = new Uint8Array([1]);
that.fs.open('/myfile', 'w', function(error, result) {
if(error) throw error;
var fd = result;
that.fs.write(fd, buffer, 0, buffer.length, 0, function(error, result) {
if(error) throw error;
that.fs.close(fd, function(error) {
if(error) throw error;
that.fs.truncate('/myfile', 1, function(error) {
_error = error;
that.fs.readFile('/myfile', function(error, result) {
if(error) throw error;
_result = result;
complete = true;
});
});
});
});
});
waitsFor(function() {
return complete;
}, 'test to complete', DEFAULT_TIMEOUT);
runs(function() {
expect(_error).toEqual(null);
expect(_result).toEqual(truncated);
});
});
it('should pad a file with zeros when the length is greater than the file size', function() {
var complete = false;
var _error, _result;
var that = this;
var buffer = new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8]);
var truncated = new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8, 0]);
that.fs.open('/myfile', 'w', function(error, result) {
if(error) throw error;
var fd = result;
that.fs.write(fd, buffer, 0, buffer.length, 0, function(error, result) {
if(error) throw error;
that.fs.close(fd, function(error) {
if(error) throw error;
that.fs.truncate('/myfile', 9, function(error) {
_error = error;
that.fs.readFile('/myfile', function(error, result) {
if(error) throw error;
_result = result;
complete = true;
});
});
});
});
});
waitsFor(function() {
return complete;
}, 'test to complete', DEFAULT_TIMEOUT);
runs(function() {
expect(_error).toEqual(null);
expect(_result).toEqual(truncated);
});
});
it('should update the file size', function() {
var complete = false;
var _error, _result;
var that = this;
var buffer = new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8]);
that.fs.open('/myfile', 'w', function(error, result) {
if(error) throw error;
var fd = result;
that.fs.write(fd, buffer, 0, buffer.length, 0, function(error, result) {
if(error) throw error;
that.fs.close(fd, function(error) {
if(error) throw error;
that.fs.truncate('/myfile', 0, function(error) {
_error = error;
that.fs.stat('/myfile', function(error, result) {
if(error) throw error;
_result = result;
complete = true;
});
});
});
});
});
waitsFor(function() {
return complete;
}, 'test to complete', DEFAULT_TIMEOUT);
runs(function() {
expect(_error).toEqual(null);
expect(_result.size).toEqual(0);
});
});
it('should truncate a valid descriptor', function() {
var complete = false;
var _error, _result;
var that = this;
var buffer = new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8]);
that.fs.open('/myfile', 'w', function(error, result) {
if(error) throw error;
var fd = result;
that.fs.write(fd, buffer, 0, buffer.length, 0, function(error, result) {
if(error) throw error;
that.fs.ftruncate(fd, 0, function(error) {
_error = error;
that.fs.fstat(fd, function(error, result) {
if(error) throw error;
_result = result;
complete=true;
});
});
});
});
waitsFor(function() {
return complete;
}, 'test to complete', DEFAULT_TIMEOUT);
runs(function() {
expect(_error).toEqual(null);
expect(_result.size).toEqual(0);
});
});
it('should follow symbolic links', function() {
var complete = false;
var _error, _result, _result2;
var that = this;
var buffer = new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8]);
that.fs.open('/myfile', 'w', function(error, result) {
if(error) throw error;
var fd = result;
that.fs.write(fd, buffer, 0, buffer.length, 0, function(error, result) {
if(error) throw error;
that.fs.close(fd, function(error) {
if(error) throw error;
that.fs.symlink('/myfile', '/mylink', function(error) {
if(error) throw error;
that.fs.truncate('/mylink', 0, function(error) {
_error = error;
that.fs.stat('/myfile', function(error, result) {
if(error) throw error;
_result = result;
that.fs.lstat('/mylink', function(error, result) {
if(error) throw error;
_result2 = result;
complete=true;
});
});
});
});
});
});
});
waitsFor(function() {
return complete;
}, 'test to complete', DEFAULT_TIMEOUT);
runs(function() {
expect(_error).toEqual(null);
expect(_result.size).toEqual(0);
expect(_result2.size).not.toEqual(0);
});
});
});
});

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@ -26,6 +26,7 @@ define([
"spec/fs.lseek.spec",
"spec/fs.symlink.spec",
"spec/fs.readlink.spec",
"spec/fs.truncate.spec",
"spec/path-resolution.spec",
// IDBFS.FileSystem.providers.*