SystemLibraryManager refactor - to separate package and sdk library functionality

compiler/java/com/google/dart/compiler/SdkLibraryManager.java

Index: compiler/java/com/google/dart/compiler/SdkLibraryManager.java
===================================================================
--- compiler/java/com/google/dart/compiler/SdkLibraryManager.java	(revision 0)
+++ compiler/java/com/google/dart/compiler/SdkLibraryManager.java	(revision 0)
@@ -0,0 +1,273 @@
+// Copyright (c) 2012, 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.
+
+package com.google.dart.compiler;
+
+import java.io.BufferedInputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Properties;
+
+/**
+ * A Library manager that manages system libraries 
+ */
+public class SdkLibraryManager  {
+
+  private static final String IMPORT_CONFIG = "import_%s.config";
+  
+  private HashMap<String, String> expansionMap;
+  private Map<String, SystemLibrary> hostMap;
+  private final File sdkLibPath;
+  private final URI sdkLibPathUri;
+  private final String platformName;
+  
+  private Map<URI, URI> longToShortUriMap;
+
+  private List<SystemLibrary> libraries;
+
+  public SdkLibraryManager(File sdkPath, String platformName) {
+    this.sdkLibPath = new File(sdkPath, "lib").getAbsoluteFile();
+    this.sdkLibPathUri = sdkLibPath.toURI();
+    this.platformName = platformName;
+    setLibraries(getDefaultLibraries());
+   
+  }
+  
+  public URI expandRelativeDartUri(URI uri) throws AssertionError {
+      String host = uri.getHost();
+      if (host == null) {
+        String spec = uri.getSchemeSpecificPart();
+        String replacement = expansionMap.get(spec);
+        if (replacement != null) {
+          try {
+            uri = new URI(SystemLibraryManager.DART_SCHEME + ":" + replacement);
+          } catch (URISyntaxException e) {
+            throw new AssertionError();
+          }
+        } else {
+          return null;
+        }
+      }
+      return uri;
+  }
+  
+  public URI getRelativeUri(URI fileUri) {
+    
+    if (fileUri == null || !fileUri.getScheme().equals("file")){
+      return null;
+    }
+  
+    URI relativeUri = sdkLibPathUri.relativize(fileUri);
+    if (relativeUri.getScheme() == null) {
+      try {
+        return new URI(null, null, "dart://" + relativeUri.getPath(), null, null);
+      } catch (URISyntaxException e) {
+        //$FALL-THROUGH$
+      }
+    } 
+    return null;
+  }
+  
+  public URI getShortUri(URI uri) {
+    URI shortUri = longToShortUriMap.get(uri);
+    if (shortUri != null){
+      return shortUri;
+    }
+    shortUri = getRelativeUri(uri);
+    if (shortUri != null){
+      try {
+        return new URI(null, null, shortUri.getScheme() + ":" +  shortUri.getHost() + shortUri.getPath(),null, null);
+      } catch (URISyntaxException e) {
+      }
+    }
+    return null;
+  }
+  
+  public URI translateDartUri(URI uri) {
+   
+      String host = uri.getHost();
+      SystemLibrary library = hostMap.get(host);
+      if (library != null) {
+        return library.translateUri(uri);
+      }
+      if (host != null) {
+        return new File(getSdkLibPath(), host).toURI().resolve("." + uri.getPath());
+      }
+      throw new RuntimeException("No system library defined for " + uri);
+   
+  }
+  
+  
+  public Collection<String> getAllLibrarySpecs() {
+    Collection<String> result = new ArrayList<String>(libraries.size());
+    for (SystemLibrary lib : libraries) {
+      result.add("dart:" + lib.getShortName());
+    }
+    return result;
+  }
+  
+  
+  /**
+   * Scan the directory returned by {@link #getLibrariesDir()} looking for libraries of the form
+   * libraries/<name>/<name>_<platform>.dart and libraries/<name>/<name>.dart where <platform> is
+   * the value initialized in the {@link SdkLibraryManager}.
+   */
+  protected SystemLibrary[] getDefaultLibraries() {
+    libraries = new ArrayList<SystemLibrary>();
+    longToShortUriMap = new HashMap<URI, URI>();
+
+    // Cycle through the import.config, extracting explicit mappings and searching directories
+    URI base = this.sdkLibPathUri;
+    Properties importConfig = getImportConfig();
+    HashSet<String> explicitShortNames = new HashSet<String>();
+    for (Entry<Object, Object> entry : importConfig.entrySet()) {
+      String shortName = ((String) entry.getKey()).trim();
+      String path = ((String) entry.getValue()).trim();
+
+      File file;
+      try {
+        file = new File(base.resolve(new URI(null, null, path, null, null)).normalize());
+      } catch (URISyntaxException e) {
+        continue;
+      }
+      if (!file.exists()) {
+        throw new InternalCompilerException("Can't find system library dart:" + shortName
+                                            + " at " + file);
+      }
+
+      // If the shortName ends with ":" then search the associated directory for libraries
+
+      if (shortName.endsWith(":")) {
+        if (!file.isDirectory()) {
+          continue;
+        }
+        for (File child : file.listFiles()) {
+          String host = child.getName();
+          // Do not overwrite explicit shortName to dart file mappings
+          if (explicitShortNames.contains(shortName + host)) {
+            continue;
+          }
+          if (!child.isDirectory()) {
+            continue;
+          }
+          File dartFile = new File(child, child.getName() + ".dart");
+          if (!dartFile.isFile()) {
+            // addLib() will throw an exception. In this case, we are just scanning
+            // for libraries and don't want the error to be fatal.
+            continue;
+          }
+          addLib(shortName, host, host, child, dartFile.getName());
+        }
+      } else {
+        // Otherwise treat the entry as an explicit shortName to dart file mapping
+        int index = shortName.indexOf(':');
+        if (index == -1) {
+          continue;
+        }
+        explicitShortNames.add(shortName);
+        String scheme = shortName.substring(0, index + 1);
+        String name = shortName.substring(index + 1);
+        String host = file.getParentFile().getName();
+        addLib(scheme, host, name, file.getParentFile(), file.getName());
+      }
+    }
+    return libraries.toArray(new SystemLibrary[libraries.size()]);
+  }
+
+  /**
+   * Read the import.config content and return it as a collection of key/value pairs
+   */
+  protected Properties getImportConfig() {
+    Properties importConfig = new Properties();
+    InputStream stream = getImportConfigStream();
+    try {
+      importConfig.load(stream);
+    } catch (IOException ignored) {
+    } finally {
+      try {
+        stream.close();
+      } catch (IOException ignored) {
+      }
+    }
+    return importConfig;
+  }
+
+  protected InputStream getImportConfigStream() {
+    File file = new File(new File(sdkLibPath, "config"),
+                         String.format(IMPORT_CONFIG, platformName));
+    if (!file.exists()) {
+      throw new InternalCompilerException("Failed to find " + file.toString()
+                                          + ".  Is dart-sdk path correct?");
+    }
+    try {
+      return new BufferedInputStream(new FileInputStream(file));
+    } catch (FileNotFoundException e) {
+      throw new InternalCompilerException("Failed to open " + file);
+    }
+  }
+  
+  
+  private boolean addLib(String scheme, String host, String name, File dir, String libFileName)
+      throws AssertionError {
+    File libFile = new File(dir, libFileName);
+    if (!libFile.isFile()) {
+      throw new InternalCompilerException("Error mapping dart:" + host + ", path "
+          + libFile.getAbsolutePath() + " is not a file.");
+    }
+    SystemLibrary lib = new SystemLibrary(name, host, libFileName, dir);
+    libraries.add(lib);
+    String libSpec = scheme + name;
+    URI libUri;
+    URI expandedUri;
+    try {
+      libUri = new URI(libSpec);
+      expandedUri = new URI("dart:" + "//" + host + "/" + libFileName);
+    } catch (URISyntaxException e) {
+      throw new AssertionError(e);
+    }
+    URI resolvedUri = lib.translateUri(expandedUri);
+    longToShortUriMap.put(resolvedUri, libUri);
+    longToShortUriMap.put(expandedUri, libUri);
+    return true;
+  }
+
+  /**
+   * Register system libraries for the "dart:" protocol such that dart:[shortLibName] (e.g.
+   * "dart:html") will automatically be expanded to dart://[host]/[pathToLib] (e.g.
+   * dart://html/html.dart)
+   */
+  private void setLibraries(SystemLibrary[] newLibraries) {
+    libraries = new ArrayList<SystemLibrary>();
+    hostMap = new HashMap<String, SystemLibrary>();
+    expansionMap = new HashMap<String, String>();
+    for (SystemLibrary library : newLibraries) {
+      String host = library.getHost();
+      SystemLibrary existingLib = hostMap.get(host);
+      if (existingLib != null) {
+        libraries.remove(existingLib);
+      }
+      libraries.add(library);
+      hostMap.put(host, library);
+      expansionMap.put(library.getShortName(),
+          "//" + host + "/" + library.getPathToLib());
+    }
+  }
+  
+  public File getSdkLibPath() {
+    return sdkLibPath;
+  }
+
+}