4823: Add flush() to ArvadosFile. Fix tests to avoid using internal APIs. Fix
[arvados.git] / sdk / python / arvados / collection.py
index 82b97456f7ac1d86a49c80ca125f38db577c28e3..b0cdd92251096fe671be48a07a38400dcca14c60 100644 (file)
@@ -3,15 +3,18 @@ import logging
 import os
 import re
 import errno
+import hashlib
 import time
+import threading
 
 from collections import deque
 from stat import *
 
-from .arvfile import split, FileLikeObjectBase, ArvadosFile, ArvadosFileWriter, ArvadosFileReader, _BlockManager, synchronized, must_be_writable, SYNC_READONLY, SYNC_EXPLICIT, NoopLock
-from keep import *
-from .stream import StreamReader, normalize_stream, locator_block_size
-from .ranges import Range, LocatorAndRange
+from .arvfile import split, _FileLikeObjectBase, ArvadosFile, ArvadosFileWriter, ArvadosFileReader, _BlockManager, synchronized, must_be_writable, NoopLock
+from keep import KeepLocator, KeepClient
+from .stream import StreamReader
+from ._normalize_stream import normalize_stream
+from ._ranges import Range, LocatorAndRange
 from .safeapi import ThreadSafeApiCache
 import config
 import errors
@@ -35,7 +38,8 @@ class CollectionBase(object):
         return self._keep_client
 
     def stripped_manifest(self):
-        """
+        """Get the manifest with locator hints stripped.
+
         Return the manifest for the current collection with all
         non-portable hints (i.e., permission signatures and other
         hints other than size hints) removed from the locators.
@@ -54,7 +58,7 @@ class CollectionBase(object):
         return ''.join(clean)
 
 
-class _WriterFile(FileLikeObjectBase):
+class _WriterFile(_FileLikeObjectBase):
     def __init__(self, coll_writer, name):
         super(_WriterFile, self).__init__(name, 'wb')
         self.dest = coll_writer
@@ -63,16 +67,16 @@ class _WriterFile(FileLikeObjectBase):
         super(_WriterFile, self).close()
         self.dest.finish_current_file()
 
-    @FileLikeObjectBase._before_close
+    @_FileLikeObjectBase._before_close
     def write(self, data):
         self.dest.write(data)
 
-    @FileLikeObjectBase._before_close
+    @_FileLikeObjectBase._before_close
     def writelines(self, seq):
         for data in seq:
             self.write(data)
 
-    @FileLikeObjectBase._before_close
+    @_FileLikeObjectBase._before_close
     def flush(self):
         self.dest.flush_data()
 
@@ -494,10 +498,7 @@ class SynchronizedCollectionBase(CollectionBase):
     def _my_block_manager(self):
         raise NotImplementedError()
 
-    def _populate(self):
-        raise NotImplementedError()
-
-    def sync_mode(self):
+    def writable(self):
         raise NotImplementedError()
 
     def root_collection(self):
@@ -506,6 +507,9 @@ class SynchronizedCollectionBase(CollectionBase):
     def notify(self, event, collection, name, item):
         raise NotImplementedError()
 
+    def stream_name(self):
+        raise NotImplementedError()
+
     @must_be_writable
     @synchronized
     def find_or_create(self, path, create_type):
@@ -517,22 +521,18 @@ class SynchronizedCollectionBase(CollectionBase):
         the path.
 
         :create_type:
-          One of `arvado.collection.FILE` or
-          `arvado.collection.COLLECTION`.  If the path is not found, and value
+          One of `arvados.collection.FILE` or
+          `arvados.collection.COLLECTION`.  If the path is not found, and value
           of create_type is FILE then create and return a new ArvadosFile for
           the last path component.  If COLLECTION, then create and return a new
           Collection for the last path component.
 
         """
 
-        pathcomponents = path.split("/")
-        if pathcomponents[0] == '.':
-            del pathcomponents[0]
-
-        if pathcomponents and pathcomponents[0]:
+        pathcomponents = path.split("/", 1)
+        if pathcomponents[0]:
             item = self._items.get(pathcomponents[0])
             if len(pathcomponents) == 1:
-                # item must be a file
                 if item is None:
                     # create new file
                     if create_type == COLLECTION:
@@ -550,11 +550,10 @@ class SynchronizedCollectionBase(CollectionBase):
                     self._items[pathcomponents[0]] = item
                     self._modified = True
                     self.notify(ADD, self, pathcomponents[0], item)
-                del pathcomponents[0]
                 if isinstance(item, SynchronizedCollectionBase):
-                    return item.find_or_create("/".join(pathcomponents), create_type)
+                    return item.find_or_create(pathcomponents[1], create_type)
                 else:
-                    raise errors.ArgumentError("Interior path components must be subcollection")
+                    raise IOError((errno.ENOTDIR, "Interior path components must be subcollection"))
         else:
             return self
 
@@ -566,23 +565,21 @@ class SynchronizedCollectionBase(CollectionBase):
         found.
 
         """
-        pathcomponents = path.split("/")
-        if pathcomponents[0] == '.':
-            del pathcomponents[0]
+        if not path:
+            raise errors.ArgumentError("Parameter 'path' must not be empty.")
 
-        if pathcomponents and pathcomponents[0]:
-            item = self._items.get(pathcomponents[0])
-            if len(pathcomponents) == 1:
-                # item must be a file
-                return item
-            else:
-                del pathcomponents[0]
-                if isinstance(item, SynchronizedCollectionBase):
-                    return item.find("/".join(pathcomponents))
-                else:
-                    raise errors.ArgumentError("Interior path components must be subcollection")
+        pathcomponents = path.split("/", 1)
+        item = self._items.get(pathcomponents[0])
+        if len(pathcomponents) == 1:
+            return item
         else:
-            return self
+            if isinstance(item, SynchronizedCollectionBase):
+                if pathcomponents[1]:
+                    return item.find(pathcomponents[1])
+                else:
+                    return item
+            else:
+                raise IOError((errno.ENOTDIR, "Interior path components must be subcollection"))
 
     def mkdirs(path):
         """Recursive subcollection create.
@@ -593,7 +590,7 @@ class SynchronizedCollectionBase(CollectionBase):
         """
         return self.find_or_create(path, COLLECTION)
 
-    def open(self, path, mode):
+    def open(self, path, mode="r"):
         """Open a file-like object for access.
 
         :path:
@@ -613,10 +610,10 @@ class SynchronizedCollectionBase(CollectionBase):
         """
         mode = mode.replace("b", "")
         if len(mode) == 0 or mode[0] not in ("r", "w", "a"):
-            raise ArgumentError("Bad mode '%s'" % mode)
+            raise errors.ArgumentError("Bad mode '%s'" % mode)
         create = (mode != "r")
 
-        if create and self.sync_mode() == SYNC_READONLY:
+        if create and not self.writable():
             raise IOError((errno.EROFS, "Collection is read only"))
 
         if create:
@@ -632,15 +629,16 @@ class SynchronizedCollectionBase(CollectionBase):
         if mode[0] == "w":
             arvfile.truncate(0)
 
+        name = os.path.basename(path)
+
         if mode == "r":
-            return ArvadosFileReader(arvfile, path, mode, num_retries=self.num_retries)
+            return ArvadosFileReader(arvfile, name, mode, num_retries=self.num_retries)
         else:
-            return ArvadosFileWriter(arvfile, path, mode, num_retries=self.num_retries)
+            return ArvadosFileWriter(arvfile, name, mode, num_retries=self.num_retries)
 
     @synchronized
     def modified(self):
-        """Test if the collection (or any subcollection or file) has been modified
-        since it was created."""
+        """Test if the collection (or any subcollection or file) has been modified."""
         if self._modified:
             return True
         for k,v in self._items.items():
@@ -660,22 +658,18 @@ class SynchronizedCollectionBase(CollectionBase):
         """Iterate over names of files and collections contained in this collection."""
         return iter(self._items.keys())
 
-    @synchronized
-    def iterkeys(self):
-        """Iterate over names of files and collections directly contained in this collection."""
-        return self._items.keys()
-
     @synchronized
     def __getitem__(self, k):
-        """Get a file or collection that is directly contained by this collection.  If
-        you want to search a path, use `find()` instead.
+        """Get a file or collection that is directly contained by this collection.
+
+        If you want to search a path, use `find()` instead.
+
         """
         return self._items[k]
 
     @synchronized
     def __contains__(self, k):
-        """If there is a file or collection a directly contained by this collection
-        with name `k`."""
+        """Test if there is a file or collection a directly contained by this collection."""
         return k in self._items
 
     @synchronized
@@ -718,42 +712,73 @@ class SynchronizedCollectionBase(CollectionBase):
         :recursive:
           Specify whether to remove non-empty subcollections (True), or raise an error (False).
         """
-        pathcomponents = path.split("/")
-        if pathcomponents[0] == '.':
-            # Remove '.' from the front of the path
-            del pathcomponents[0]
 
-        if len(pathcomponents) > 0:
-            item = self._items.get(pathcomponents[0])
-            if item is None:
-                raise IOError((errno.ENOENT, "File not found"))
-            if len(pathcomponents) == 1:
-                if isinstance(self._items[pathcomponents[0]], SynchronizedCollectionBase) and len(self._items[pathcomponents[0]]) > 0 and not recursive:
-                    raise IOError((errno.ENOTEMPTY, "Subcollection not empty"))
-                deleteditem = self._items[pathcomponents[0]]
-                del self._items[pathcomponents[0]]
-                self._modified = True
-                self.notify(DEL, self, pathcomponents[0], deleteditem)
-            else:
-                del pathcomponents[0]
-                item.remove("/".join(pathcomponents))
-        else:
+        if not path:
+            raise errors.ArgumentError("Parameter 'path' must not be empty.")
+
+        pathcomponents = path.split("/", 1)
+        item = self._items.get(pathcomponents[0])
+        if item is None:
             raise IOError((errno.ENOENT, "File not found"))
+        if len(pathcomponents) == 1:
+            if isinstance(self._items[pathcomponents[0]], SynchronizedCollectionBase) and len(self._items[pathcomponents[0]]) > 0 and not recursive:
+                raise IOError((errno.ENOTEMPTY, "Subcollection not empty"))
+            deleteditem = self._items[pathcomponents[0]]
+            del self._items[pathcomponents[0]]
+            self._modified = True
+            self.notify(DEL, self, pathcomponents[0], deleteditem)
+        else:
+            item.remove(pathcomponents[1])
 
-    def _cloneinto(self, target):
-        for k,v in self._items.items():
-            target._items[k] = v.clone(target)
+    def _clonefrom(self, source):
+        for k,v in source.items():
+            self._items[k] = v.clone(self)
 
     def clone(self):
         raise NotImplementedError()
 
+    @must_be_writable
+    @synchronized
+    def add(self, source_obj, target_name, overwrite=False):
+        """Copy a file or subcollection to this collection.
+
+        :source_obj:
+          An ArvadosFile, or Subcollection object
+
+        :target_name:
+          Destination item name.  If the target name already exists and is a
+          file, this will raise an error unless you specify `overwrite=True`.
+
+        :overwrite:
+          Whether to overwrite target file if it already exists.
+
+        """
+
+        if target_name in self and not overwrite:
+            raise IOError((errno.EEXIST, "File already exists"))
+
+        modified_from = None
+        if target_name in self:
+            modified_from = self[target_name]
+
+        # Actually make the copy.
+        dup = source_obj.clone(self)
+        self._items[target_name] = dup
+        self._modified = True
+
+        if modified_from:
+            self.notify(MOD, self, target_name, (modified_from, dup))
+        else:
+            self.notify(ADD, self, target_name, dup)
+
+
     @must_be_writable
     @synchronized
     def copy(self, source, target_path, source_collection=None, overwrite=False):
         """Copy a file or subcollection to a new path in this collection.
 
         :source:
-          An ArvadosFile, Subcollection, or string with a path to source file or subcollection
+          A string with a path to source file or subcollection, or an actual ArvadosFile or Subcollection object.
 
         :target_path:
           Destination file or path.  If the target path already exists and is a
@@ -791,27 +816,11 @@ class SynchronizedCollectionBase(CollectionBase):
 
         target_dir = self.find_or_create("/".join(targetcomponents[0:-1]), COLLECTION)
 
-        with target_dir.lock:
-            if target_name in target_dir:
-                if isinstance(target_dir[target_name], SynchronizedCollectionBase) and sourcecomponents:
-                    target_dir = target_dir[target_name]
-                    target_name = sourcecomponents[-1]
-                elif not overwrite:
-                    raise IOError((errno.EEXIST, "File already exists"))
-
-            modified_from = None
-            if target_name in target_dir:
-                modified_from = target_dir[target_name]
+        if target_name in target_dir and isinstance(self[target_name], SynchronizedCollectionBase) and sourcecomponents:
+            target_dir = target_dir[target_name]
+            target_name = sourcecomponents[-1]
 
-            # Actually make the copy.
-            dup = source_obj.clone(target_dir)
-            target_dir._items[target_name] = dup
-            target_dir._modified = True
-
-        if modified_from:
-            self.notify(MOD, target_dir, target_name, (modified_from, dup))
-        else:
-            self.notify(ADD, target_dir, target_name, dup)
+        target_dir.add(source_obj, target_name, overwrite)
 
     @synchronized
     def manifest_text(self, stream_name=".", strip=False, normalize=False):
@@ -832,10 +841,10 @@ class SynchronizedCollectionBase(CollectionBase):
 
         """
 
-        portable_locators = strip
         if self.modified() or self._manifest_text is None or normalize:
             item  = self
             stream = {}
+            buf = []
             sorted_keys = sorted(item.keys())
             for filename in [s for s in sorted_keys if isinstance(item[s], ArvadosFile)]:
                 # Create a stream per file `k`
@@ -845,32 +854,32 @@ class SynchronizedCollectionBase(CollectionBase):
                     loc = segment.locator
                     if arvfile.parent._my_block_manager().is_bufferblock(loc):
                         loc = arvfile.parent._my_block_manager().get_bufferblock(loc).locator()
-                    if portable_locators:
+                    if strip:
                         loc = KeepLocator(loc).stripped()
-                    filestream.append(LocatorAndRange(loc, locator_block_size(loc),
+                    filestream.append(LocatorAndRange(loc, KeepLocator(loc).size,
                                          segment.segment_offset, segment.range_size))
                 stream[filename] = filestream
             if stream:
-                buf += ' '.join(normalize_stream(stream_name, stream))
-                buf += "\n"
+                buf.append(" ".join(normalize_stream(stream_name, stream)) + "\n")
             for dirname in [s for s in sorted_keys if isinstance(item[s], SynchronizedCollectionBase)]:
-                buf += item[dirname].manifest_text(stream_name=os.path.join(stream_name, dirname), portable_locators=portable_locators)
-            return buf
+                buf.append(item[dirname].manifest_text(stream_name=os.path.join(stream_name, dirname), strip=strip))
+            return "".join(buf)
         else:
-            if portable_locators:
+            if strip:
                 return self.stripped_manifest()
             else:
                 return self._manifest_text
 
     @synchronized
     def diff(self, end_collection, prefix=".", holding_collection=None):
-        """
-        Generate list of add/modify/delete actions which, when given to `apply`, will
-        change `self` to match `end_collection`
+        """Generate list of add/modify/delete actions.
+
+        When given to `apply`, will change `self` to match `end_collection`
+
         """
         changes = []
         if holding_collection is None:
-            holding_collection = Collection(api_client=self._my_api(), keep_client=self._my_keep(), sync=SYNC_EXPLICIT)
+            holding_collection = Collection(api_client=self._my_api(), keep_client=self._my_keep())
         for k in self:
             if k not in end_collection:
                changes.append((DEL, os.path.join(prefix, k), self[k].clone(holding_collection)))
@@ -956,10 +965,14 @@ class SynchronizedCollectionBase(CollectionBase):
 
 
 class Collection(SynchronizedCollectionBase):
-    """Represents the root of an Arvados Collection, which may be associated with
-    an API server Collection record.
+    """Represents the root of an Arvados Collection.
+
+    This class is threadsafe.  The root collection object, all subcollections
+    and files are protected by a single lock (i.e. each access locks the entire
+    collection).
 
-    Brief summary of useful methods:
+    Brief summary of
+    useful methods:
 
     :To read an existing file:
       `c.open("myfile", "r")`
@@ -985,18 +998,17 @@ class Collection(SynchronizedCollectionBase):
     :To merge remote changes into this object:
       `c.update()`
 
-    This class is threadsafe.  The root collection object, all subcollections
-    and files are protected by a single lock (i.e. each access locks the entire
-    collection).
+    Must be associated with an API server Collection record (during
+    initialization, or using `save_new`) to use `save` or `update`
 
     """
 
     def __init__(self, manifest_locator_or_text=None,
-                 parent=None,
-                 apiconfig=None,
                  api_client=None,
                  keep_client=None,
                  num_retries=None,
+                 parent=None,
+                 apiconfig=None,
                  block_manager=None):
         """Collection constructor.
 
@@ -1029,14 +1041,12 @@ class Collection(SynchronizedCollectionBase):
         else:
             self._config = config.settings()
 
-        self.num_retries = num_retries if num_retries is not None else 2
+        self.num_retries = num_retries if num_retries is not None else 0
         self._manifest_locator = None
         self._manifest_text = None
         self._api_response = None
 
-        self._sync = SYNC_EXPLICIT
-        if not self.lock:
-            self.lock = threading.RLock()
+        self.lock = threading.RLock()
         self.callbacks = []
         self.events = None
 
@@ -1051,28 +1061,31 @@ class Collection(SynchronizedCollectionBase):
                 raise errors.ArgumentError(
                     "Argument to CollectionReader must be a manifest or a collection UUID")
 
-            self._populate()
-
+            try:
+                self._populate()
+            except (IOError, errors.SyntaxError) as e:
+                raise errors.ArgumentError("Error processing manifest text: %s", e)
 
     def root_collection(self):
         return self
 
-    def sync_mode(self):
-        return self._sync
+    def stream_name(self):
+        return "."
+
+    def writable(self):
+        return True
 
     @synchronized
     @retry_method
     def update(self, other=None, num_retries=None):
-        """Fetch the latest collection record on the API server and merge it with the
-        current collection contents.
+        """Merge the latest collection on the API server with the current collection."""
 
-        """
         if other is None:
             if self._manifest_locator is None:
                 raise errors.ArgumentError("`other` is None but collection does not have a manifest_locator uuid")
             response = self._my_api().collections().get(uuid=self._manifest_locator).execute(num_retries=num_retries)
-            other = import_manifest(response["manifest_text"])
-        baseline = import_manifest(self._manifest_text)
+            other = CollectionReader(response["manifest_text"])
+        baseline = CollectionReader(self._manifest_text)
         self.apply(baseline.diff(other))
 
     @synchronized
@@ -1088,7 +1101,7 @@ class Collection(SynchronizedCollectionBase):
             if self._api_client is None:
                 self._my_api()
             else:
-                self._keep_client = KeepClient(api=self._api_client)
+                self._keep_client = KeepClient(api_client=self._api_client)
         return self._keep_client
 
     @synchronized
@@ -1147,7 +1160,7 @@ class Collection(SynchronizedCollectionBase):
             error_via_keep = self._populate_from_keep()
         if self._manifest_text is None:
             # Nothing worked!
-            raise arvados.errors.NotFoundError(
+            raise errors.NotFoundError(
                 ("Failed to retrieve collection '{}' " +
                  "from either API server ({}) or Keep ({})."
                  ).format(
@@ -1156,7 +1169,7 @@ class Collection(SynchronizedCollectionBase):
                     error_via_keep))
         # populate
         self._baseline_manifest = self._manifest_text
-        import_manifest(self._manifest_text, self)
+        self._import_manifest(self._manifest_text)
 
 
     def _has_collection_uuid(self):
@@ -1167,20 +1180,27 @@ class Collection(SynchronizedCollectionBase):
 
     def __exit__(self, exc_type, exc_value, traceback):
         """Support scoped auto-commit in a with: block."""
-        if self._sync != SYNC_READONLY and self._has_collection_uuid():
-            self.save()
+        if exc_type is not None:
+            if self.writable() and self._has_collection_uuid():
+                self.save()
         if self._block_manager is not None:
             self._block_manager.stop_threads()
 
     @synchronized
-    def clone(self, new_parent=None, new_sync=SYNC_READONLY, new_config=None):
+    def manifest_locator(self):
+        """Get the manifest locator.  May be None."""
+        return self._manifest_locator
+
+    @synchronized
+    def clone(self, new_parent=None, readonly=False, new_config=None):
         if new_config is None:
             new_config = self._config
-        newcollection = Collection(parent=new_parent, apiconfig=new_config, sync=SYNC_EXPLICIT)
-        if new_sync == SYNC_READONLY:
-            newcollection.lock = NoopLock()
-        self._cloneinto(newcollection)
-        newcollection._sync = new_sync
+        if readonly:
+            newcollection = CollectionReader(parent=new_parent, apiconfig=new_config)
+        else:
+            newcollection = Collection(parent=new_parent, apiconfig=new_config)
+
+        newcollection._clonefrom(self)
         return newcollection
 
     @synchronized
@@ -1193,11 +1213,34 @@ class Collection(SynchronizedCollectionBase):
         """
         return self._api_response
 
+    def find_or_create(self, path, create_type):
+        """See `SynchronizedCollectionBase.find_or_create`"""
+        if path == ".":
+            return self
+        else:
+            return super(Collection, self).find_or_create(path[2:] if path.startswith("./") else path, create_type)
+
+    def find(self, path):
+        """See `SynchronizedCollectionBase.find`"""
+        if path == ".":
+            return self
+        else:
+            return super(Collection, self).find(path[2:] if path.startswith("./") else path)
+
+    def remove(self, path, recursive=False):
+        """See `SynchronizedCollectionBase.remove`"""
+        if path == ".":
+            raise errors.ArgumentError("Cannot remove '.'")
+        else:
+            return super(Collection, self).remove(path[2:] if path.startswith("./") else path, recursive)
+
     @must_be_writable
     @synchronized
     @retry_method
     def save(self, merge=True, num_retries=None):
-        """Commit pending buffer blocks to Keep, merge with remote record (if
+        """Save collection to an existing collection record.
+
+        Commit pending buffer blocks to Keep, merge with remote record (if
         update=True), write the manifest to Keep, and update the collection
         record.
 
@@ -1205,10 +1248,13 @@ class Collection(SynchronizedCollectionBase):
         the API server.  If you want to save a manifest to Keep only, see
         `save_new()`.
 
-        :update:
+        :merge:
           Update and merge remote changes before saving.  Otherwise, any
           remote changes will be ignored and overwritten.
 
+        :num_retries:
+          Retry count on API calls (if None,  use the collection default)
+
         """
         if self.modified():
             if not self._has_collection_uuid():
@@ -1232,17 +1278,18 @@ class Collection(SynchronizedCollectionBase):
     @synchronized
     @retry_method
     def save_new(self, name=None, create_collection_record=True, owner_uuid=None, ensure_unique_name=False, num_retries=None):
-        """Commit pending buffer blocks to Keep, write the manifest to Keep, and create
-        a new collection record (if create_collection_record True).
+        """Save collection to a new collection record.
 
+        Commit pending buffer blocks to Keep, write the manifest to Keep, and
+        create a new collection record (if create_collection_record True).
         After creating a new collection record, this Collection object will be
         associated with the new record used by `save()`.
 
         :name:
           The collection name.
 
-        :keep_only:
-          Only save the manifest to keep, do not create a collection record.
+        :create_collection_record:
+          If True, create a collection record.  If False, only save the manifest to keep.
 
         :owner_uuid:
           the user, or project uuid that will own this collection.
@@ -1253,6 +1300,9 @@ class Collection(SynchronizedCollectionBase):
           if it conflicts with a collection with the same name and owner.  If
           False, a name conflict will result in an error.
 
+        :num_retries:
+          Retry count on API calls (if None,  use the collection default)
+
         """
         self._my_block_manager().commit_all()
         self._my_keep().put(self.manifest_text(strip=True), num_retries=num_retries)
@@ -1299,10 +1349,6 @@ class Collection(SynchronizedCollectionBase):
         if len(self) > 0:
             raise ArgumentError("Can only import manifest into an empty collection")
 
-        into_collection = self
-        save_sync = into_collection.sync_mode()
-        into_collection._sync = None
-
         STREAM_NAME = 0
         BLOCKS = 1
         SEGMENTS = 2
@@ -1310,9 +1356,9 @@ class Collection(SynchronizedCollectionBase):
         stream_name = None
         state = STREAM_NAME
 
-        for n in re.finditer(r'(\S+)(\s+|$)', manifest_text):
-            tok = n.group(1)
-            sep = n.group(2)
+        for token_and_separator in re.finditer(r'(\S+)(\s+|$)', manifest_text):
+            tok = token_and_separator.group(1)
+            sep = token_and_separator.group(2)
 
             if state == STREAM_NAME:
                 # starting a new stream
@@ -1324,22 +1370,26 @@ class Collection(SynchronizedCollectionBase):
                 continue
 
             if state == BLOCKS:
-                s = re.match(r'[0-9a-f]{32}\+(\d+)(\+\S+)*', tok)
-                if s:
-                    blocksize = long(s.group(1))
+                block_locator = re.match(r'[0-9a-f]{32}\+(\d+)(\+\S+)*', tok)
+                if block_locator:
+                    blocksize = long(block_locator.group(1))
                     blocks.append(Range(tok, streamoffset, blocksize))
                     streamoffset += blocksize
                 else:
                     state = SEGMENTS
 
             if state == SEGMENTS:
-                s = re.search(r'^(\d+):(\d+):(\S+)', tok)
-                if s:
-                    pos = long(s.group(1))
-                    size = long(s.group(2))
-                    name = s.group(3).replace('\\040', ' ')
-                    f = into_collection.find_or_create("%s/%s" % (stream_name, name), FILE)
-                    f.add_segment(blocks, pos, size)
+                file_segment = re.search(r'^(\d+):(\d+):(\S+)', tok)
+                if file_segment:
+                    pos = long(file_segment.group(1))
+                    size = long(file_segment.group(2))
+                    name = file_segment.group(3).replace('\\040', ' ')
+                    filepath = os.path.join(stream_name, name)
+                    afile = self.find_or_create(filepath, FILE)
+                    if isinstance(afile, ArvadosFile):
+                        afile.add_segment(blocks, pos, size)
+                    else:
+                        raise errors.SyntaxError("File %s conflicts with stream of the same name.", filepath)
                 else:
                     # error!
                     raise errors.SyntaxError("Invalid manifest format")
@@ -1348,8 +1398,7 @@ class Collection(SynchronizedCollectionBase):
                 stream_name = None
                 state = STREAM_NAME
 
-        into_collection.set_unmodified()
-        into_collection._sync = save_sync
+        self.set_unmodified()
 
 
 class Subcollection(SynchronizedCollectionBase):
@@ -1363,12 +1412,13 @@ class Subcollection(SynchronizedCollectionBase):
     def __init__(self, parent):
         super(Subcollection, self).__init__(parent)
         self.lock = self.root_collection().lock
+        self._manifest_text = None
 
     def root_collection(self):
         return self.parent.root_collection()
 
-    def sync_mode(self):
-        return self.root_collection().sync_mode()
+    def writable(self):
+        return self.root_collection().writable()
 
     def _my_api(self):
         return self.root_collection()._my_api()
@@ -1379,42 +1429,68 @@ class Subcollection(SynchronizedCollectionBase):
     def _my_block_manager(self):
         return self.root_collection()._my_block_manager()
 
-    def _populate(self):
-        self.root_collection()._populate()
-
     def notify(self, event, collection, name, item):
         return self.root_collection().notify(event, collection, name, item)
 
+    def stream_name(self):
+        for k, v in self.parent.items():
+            if v is self:
+                return os.path.join(self.parent.stream_name(), k)
+        return '.'
+
     @synchronized
     def clone(self, new_parent):
         c = Subcollection(new_parent)
-        self._cloneinto(c)
+        c._clonefrom(self)
         return c
 
 
 class CollectionReader(Collection):
-    """A read-only collection object from an api collection record locator,
-    a portable data hash of a manifest, or raw manifest text.
+    """A read-only collection object.
 
-    See `Collection` constructor for detailed options.
+    Initialize from an api collection record locator, a portable data hash of a
+    manifest, or raw manifest text.  See `Collection` constructor for detailed
+    options.
 
     """
-    def __init__(self, *args, **kwargs):
-        if not args and not kwargs.get("manifest_locator_or_text"):
-            raise errors.ArgumentError("Must provide manifest locator or text to initialize ReadOnlyCollection")
+    def __init__(self, manifest_locator_or_text, *args, **kwargs):
+        self._in_init = True
+        super(CollectionReader, self).__init__(manifest_locator_or_text, *args, **kwargs)
+        self._in_init = False
 
         # Forego any locking since it should never change once initialized.
         self.lock = NoopLock()
 
-        super(ReadOnlyCollection, self).__init__(*args, **kwargs)
+        # Backwards compatability with old CollectionReader
+        # all_streams() and all_files()
+        self._streams = None
+
+    def writable(self):
+        return self._in_init
+
+    def _populate_streams(orig_func):
+        @functools.wraps(orig_func)
+        def populate_streams_wrapper(self, *args, **kwargs):
+            # Defer populating self._streams until needed since it creates a copy of the manifest.
+            if self._streams is None:
+                if self._manifest_text:
+                    self._streams = [sline.split()
+                                     for sline in self._manifest_text.split("\n")
+                                     if sline]
+                else:
+                    self._streams = []
+            return orig_func(self, *args, **kwargs)
+        return populate_streams_wrapper
 
-        self._sync = SYNC_READONLY
+    @_populate_streams
+    def normalize(self):
+        """Normalize the streams returned by `all_streams`.
 
-        self._streams = [sline.split()
-                         for sline in self._manifest_text.split("\n")
-                         if sline]
+        This method is kept for backwards compatability and only affects the
+        behavior of `all_streams()` and `all_files()`
+
+        """
 
-    def normalize(self):
         # Rearrange streams
         streams = {}
         for s in self.all_streams():
@@ -1429,11 +1505,12 @@ class CollectionReader(Collection):
 
         self._streams = [normalize_stream(s, streams[s])
                          for s in sorted(streams)]
-
+    @_populate_streams
     def all_streams(self):
         return [StreamReader(s, self._my_keep(), num_retries=self.num_retries)
                 for s in self._streams]
 
+    @_populate_streams
     def all_files(self):
         for s in self.all_streams():
             for f in s.all_files():