blob: 03b37b64948140c855d5ea0603c79e1eab603f48 [file] [log] [blame]
// Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
library package_config.packages_file;
import "package:charcode/ascii.dart";
import "src/util.dart" show isIdentifier;
/// Parses a `.packages` file into a map from package name to base URI.
///
/// The [source] is the byte content of a `.packages` file, assumed to be
/// UTF-8 encoded. In practice, all sinficant parts of the file must be ASCII,
/// so Latin-1 or Windows-1252 encoding will also work fine.
///
/// If the file content is available as a string, its [String.codeUnits] can
/// be used as the `source` argument of this function.
///
/// The [baseLocation] is used as a base URI to resolve all relative
/// URI references against.
/// If the content was read from a file, `baseLocation` should be the
/// location of that file.
///
/// Returns a simple mapping from package name to package location.
Map<String, Uri> parse(List<int> source, Uri baseLocation) {
int index = 0;
Map<String, Uri> result = <String, Uri>{};
while (index < source.length) {
bool isComment = false;
int start = index;
int eqIndex = -1;
int end = source.length;
int char = source[index++];
if (char == $cr || char == $lf) {
continue;
}
if (char == $equal) {
throw new FormatException("Missing package name", source, index - 1);
}
isComment = char == $hash;
while (index < source.length) {
char = source[index++];
if (char == $equal && eqIndex < 0) {
eqIndex = index - 1;
} else if (char == $cr || char == $lf) {
end = index - 1;
break;
}
}
if (isComment) continue;
if (eqIndex < 0) {
throw new FormatException("No '=' on line", source, index - 1);
}
var packageName = new String.fromCharCodes(source, start, eqIndex);
if (!isIdentifier(packageName)) {
throw new FormatException("Not a valid package name", packageName, 0);
}
var packageUri = new String.fromCharCodes(source, eqIndex + 1, end);
var packageLocation = Uri.parse(packageUri);
if (!packageLocation.path.endsWith('/')) {
packageLocation =
packageLocation.replace(path: packageLocation.path + "/");
}
packageLocation = baseLocation.resolveUri(packageLocation);
if (result.containsKey(packageName)) {
throw new FormatException(
"Same package name occured twice.", source, start);
}
result[packageName] = packageLocation;
}
return result;
}
/// Writes the mapping to a [StringSink].
///
/// If [comment] is provided, the output will contain this comment
/// with `#` in front of each line.
///
/// If [baseUri] is provided, package locations will be made relative
/// to the base URI, if possible, before writing.
void write(StringSink output, Map<String, Uri> packageMapping,
{Uri baseUri, String comment}) {
if (baseUri != null && !baseUri.isAbsolute) {
throw new ArgumentError.value(baseUri, "baseUri", "Must be absolute");
}
if (comment != null) {
for (var commentLine in comment.split('\n')) {
output.write('#');
output.writeln(commentLine);
}
} else {
output.write("# generated by package:package_config at ");
output.write(new DateTime.now());
output.writeln();
}
packageMapping.forEach((String packageName, Uri uri) {
// Validate packageName.
if (!isIdentifier(packageName)) {
throw new ArgumentError('"$packageName" is not a valid package name');
}
output.write(packageName);
output.write('=');
// If baseUri provided, make uri relative.
if (baseUri != null) {
uri = _relativize(uri, baseUri);
}
output.write(uri);
if (!uri.path.endsWith('/')) {
output.write('/');
}
output.writeln();
});
}
/// Attempts to return a relative URI for [uri].
///
/// The result URI satisfies `baseUri.resolveUri(result) == uri`,
/// but may be relative.
/// The `baseUri` must be absolute.
Uri _relativize(Uri uri, Uri baseUri) {
assert(!baseUri.isAbsolute);
if (uri.hasQuery || uri.hasFragment) {
uri = new Uri(
scheme: uri.scheme,
userInfo: uri.hasAuthority ? uri.userInfo : null,
host: uri.hasAuthority ? uri.host : null,
port: uri.hasAuthority ? uri.port : null,
path: uri.path);
}
// Already relative. We assume the caller knows what they are doing.
if (!uri.isAbsolute) return uri;
if (baseUri.scheme != uri.scheme) {
return uri;
}
// If authority differs, we could remove the scheme, but it's not worth it.
if (uri.hasAuthority != baseUri.hasAuthority) return uri;
if (uri.hasAuthority) {
if (uri.userInfo != baseUri.userInfo ||
uri.host.toLowerCase() != baseUri.host.toLowerCase() ||
uri.port != baseUri.port) {
return uri;
}
}
baseUri = _normalizePath(baseUri);
List<String> base = baseUri.pathSegments.toList();
if (base.isNotEmpty) {
base = new List<String>.from(base)..removeLast();
}
uri = _normalizePath(uri);
List<String> target = uri.pathSegments.toList();
int index = 0;
while (index < base.length && index < target.length) {
if (base[index] != target[index]) {
break;
}
index++;
}
if (index == base.length) {
return new Uri(path: target.skip(index).join('/'));
} else if (index > 0) {
return new Uri(
path: '../' * (base.length - index) + target.skip(index).join('/'));
} else {
return uri;
}
}
// TODO: inline to uri.normalizePath() when we move to 1.11
Uri _normalizePath(Uri uri) => new Uri().resolveUri(uri);