Reverting 9527

utils/pub/git_source.dart

Index: utils/pub/git_source.dart
diff --git a/utils/pub/git_source.dart b/utils/pub/git_source.dart
index 4eb7c01d483f88412285f0211ecb0f9cffaea555..ae7f53b1a2489d61a1cf4f9c7fefc5ba08121597 100644
--- a/utils/pub/git_source.dart
+++ b/utils/pub/git_source.dart
@@ -7,7 +7,6 @@
 #import('io.dart');
 #import('package.dart');
 #import('source.dart');
-#import('source_registry.dart');
 #import('utils.dart');
 
 /**
@@ -16,44 +15,32 @@
 class GitSource extends Source {
   final String name = "git";
 
-  final bool shouldCache = true;
+  // TODO(rnystrom): Git packages could in theory be cached, but that adds a
+  // lot of complexity. When you install a git package, you are installing
+  // and pinning to a specific commit. That means different installs of the
+  // same git path but at different commits need to be disambiguated in the
+  // system cache. It may also lead to a lot of garbage in the system cache.
+  // For now, we are punting and simply not caching them.
+  final bool shouldCache = false;
 
   GitSource();
 
   /**
    * Clones a Git repo to the local filesystem.
-   *
-   * The Git cache directory is a little idiosyncratic. At the top level, it
-   * contains a directory for each commit of each repository, named `<package
-   * name>-<commit hash>`. These are the canonical package directories that are
-   * linked to from the `packages/` directory.
-   *
-   * In addition, the Git system cache contains a subdirectory named `cache/`
-   * which contains a directory for each separate repository URL, named
-   * `<package name>-<url hash>`. These are used to check out the repository
-   * itself; each of the commit-specific directories are clones of a directory
-   * in `cache/`.
    */
-  Future<Package> installToSystemCache(PackageId id) {
-    var revisionCachePath;
-
+  Future<bool> install(PackageId id, String destPath) {
     return isGitInstalled.chain((installed) {
-      if (!installed) {
+      if (installed) {
+        return runProcess("git",
+            ["clone", "--progress", id.description, destPath],
+            pipeStdout: true, pipeStderr: true).
+          transform((result) => result.success);
+      } else {
         throw new Exception(
             "Cannot install '${id.name}' from Git (${id.description}).\n"
             "Please ensure Git is correctly installed.");
       }
-
-      return ensureDir(join(systemCacheRoot, 'cache'));
-    }).chain((_) => _ensureRepoCache(id))
-      .chain((_) => _revisionCachePath(id, "HEAD"))
-      .chain((path) {
-      revisionCachePath = path;
-      return exists(revisionCachePath);
-    }).chain((exists) {
-      if (exists) return new Future.immediate(null);
-      return _clone(_repoCachePath(id), revisionCachePath);
-    }).chain((_) => Package.load(revisionCachePath, systemCache.sources));
+    });
   }
 
   /**
@@ -71,67 +58,4 @@ class GitSource extends Source {
       throw new FormatException("The description must be a git URL.");
     }
   }
-
-  /**
-   * Ensure that the canonical clone of the repository referred to by [id] (the
-   * one in `<system cache>/git/cache`) exists and is up-to-date. Returns a
-   * future that completes once this is finished and throws an exception if it
-   * fails.
-   */
-  Future _ensureRepoCache(PackageId id) {
-    var path = _repoCachePath(id);
-    return exists(path).chain((exists) {
-      if (!exists) return _clone(id.description, path);
-
-      return runProcess("git", ["pull", "--force", "--progress"],
-          workingDir: path, pipeStdout: true,
-          pipeStderr: true).transform((result) {
-        if (!result.success) throw 'Git failed.';
-        return null;
-      });
-    });
-  }
-
-  /**
-   * Returns a future that completes to the revision hash of the repository for
-   * [id] at [ref], which can be any Git ref.
-   */
-  Future<String> _revisionAt(PackageId id, String ref) {
-    return runProcess("git", ["rev-parse", ref],
-        workingDir: _repoCachePath(id), pipeStderr: true).transform((result) {
-      if (!result.success) throw 'Git failed.';
-      return result.stdout[0];
-    });
-  }
-
-  /**
-   * Returns the path to the revision-specific cache of [id] at [ref], which can
-   * be any Git ref.
-   */
-  Future<String> _revisionCachePath(PackageId id, String ref) {
-    return _revisionAt(id, ref).transform((rev) {
-      var revisionCacheName = '${id.name}-$rev';
-      return join(systemCacheRoot, revisionCacheName);
-    });
-  }
-
-  /**
-   * Clones the repo at the URI [from] to the path [to] on the local filesystem.
-   */
-  Future _clone(String from, String to) {
-    return runProcess("git", ["clone", "--progress", from, to],
-        pipeStdout: true, pipeStderr: true).transform((result) {
-      if (!result.success) throw 'Git failed.';
-      return null;
-    });
-  }
-
-  /**
-   * Returns the path to the canonical clone of the repository referred to by
-   * [id] (the one in `<system cache>/git/cache`).
-   */
-  String _repoCachePath(PackageId id) {
-    var repoCacheName = '${id.name}-${sha1(id.description)}';
-    return join(systemCacheRoot, 'cache', repoCacheName);
-  }
 }