refs #13667 "Merge branch '13667-add-version-file'".
[arvados.git] / sdk / python / arvados / collection.py
index eb1449b3a9b7881d73f191269628d5b7c2264180..e38a6bd475c7b8a4aee7787a537a40656fd93b36 100644 (file)
@@ -1,9 +1,20 @@
+# Copyright (C) The Arvados Authors. All rights reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+from __future__ import absolute_import
+from future.utils import listitems, listvalues, viewkeys
+from builtins import str
+from past.builtins import basestring
+from builtins import object
 import functools
 import logging
 import os
 import re
 import errno
 import hashlib
+import datetime
+import ciso8601
 import time
 import threading
 
@@ -11,20 +22,22 @@ from collections import deque
 from stat import *
 
 from .arvfile import split, _FileLikeObjectBase, ArvadosFile, ArvadosFileWriter, ArvadosFileReader, _BlockManager, synchronized, must_be_writable, NoopLock
-from keep import KeepLocator, KeepClient
+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
-import util
-import events
+import arvados.config as config
+import arvados.errors as errors
+import arvados.util
+import arvados.events as events
 from arvados.retry import retry_method
 
 _logger = logging.getLogger('arvados.collection')
 
 class CollectionBase(object):
+    """Abstract base class for Collection classes."""
+
     def __enter__(self):
         return self
 
@@ -51,7 +64,7 @@ class CollectionBase(object):
             if fields:
                 clean_fields = fields[:1] + [
                     (re.sub(r'\+[^\d][^\+]*', '', x)
-                     if re.match(util.keep_locator_pattern, x)
+                     if re.match(arvados.util.keep_locator_pattern, x)
                      else x)
                     for x in fields[1:]]
                 clean += [' '.join(clean_fields), "\n"]
@@ -82,6 +95,8 @@ class _WriterFile(_FileLikeObjectBase):
 
 
 class CollectionWriter(CollectionBase):
+    """Deprecated, use Collection instead."""
+
     def __init__(self, api_client=None, num_retries=0, replication=None):
         """Instantiate a CollectionWriter.
 
@@ -180,7 +195,7 @@ class CollectionWriter(CollectionBase):
 
     def _work_trees(self):
         path, stream_name, max_manifest_depth = self._queued_trees[0]
-        d = util.listdir_recursive(
+        d = arvados.util.listdir_recursive(
             path, max_depth = (None if max_manifest_depth == 0 else 0))
         if d:
             self._queue_dirents(stream_name, d)
@@ -216,7 +231,11 @@ class CollectionWriter(CollectionBase):
         self.do_queued_work()
 
     def write(self, newdata):
-        if hasattr(newdata, '__iter__'):
+        if isinstance(newdata, bytes):
+            pass
+        elif isinstance(newdata, str):
+            newdata = newdata.encode()
+        elif hasattr(newdata, '__iter__'):
             for s in newdata:
                 self.write(s)
             return
@@ -256,7 +275,7 @@ class CollectionWriter(CollectionBase):
         return self._last_open
 
     def flush_data(self):
-        data_buffer = ''.join(self._data_buffer)
+        data_buffer = b''.join(self._data_buffer)
         if data_buffer:
             self._current_stream_locators.append(
                 self._my_keep().put(
@@ -307,7 +326,8 @@ class CollectionWriter(CollectionBase):
     def set_current_stream_name(self, newstreamname):
         if re.search(r'[\t\n]', newstreamname):
             raise errors.AssertionError(
-                "Manifest stream names cannot contain whitespace")
+                "Manifest stream names cannot contain whitespace: '%s'" %
+                (newstreamname))
         self._current_stream_name = '.' if newstreamname=='' else newstreamname
 
     def current_stream_name(self):
@@ -345,11 +365,12 @@ class CollectionWriter(CollectionBase):
         sending manifest_text() to the API server's "create
         collection" endpoint.
         """
-        return self._my_keep().put(self.manifest_text(), copies=self.replication)
+        return self._my_keep().put(self.manifest_text().encode(),
+                                   copies=self.replication)
 
     def portable_data_hash(self):
-        stripped = self.stripped_manifest()
-        return hashlib.md5(stripped).hexdigest() + '+' + str(len(stripped))
+        stripped = self.stripped_manifest().encode()
+        return '{}+{}'.format(hashlib.md5(stripped).hexdigest(), len(stripped))
 
     def manifest_text(self):
         self.finish_current_stream()
@@ -371,8 +392,18 @@ class CollectionWriter(CollectionBase):
             ret += locators
         return ret
 
+    def save_new(self, name=None):
+        return self._api_client.collections().create(
+            ensure_unique_name=True,
+            body={
+                'name': name,
+                'manifest_text': self.manifest_text(),
+            }).execute(num_retries=self.num_retries)
+
 
 class ResumableCollectionWriter(CollectionWriter):
+    """Deprecated, use Collection instead."""
+
     STATE_PROPS = ['_current_stream_files', '_current_stream_length',
                    '_current_stream_locators', '_current_stream_name',
                    '_current_file_name', '_current_file_pos', '_close_file',
@@ -417,7 +448,7 @@ class ResumableCollectionWriter(CollectionWriter):
         return writer
 
     def check_dependencies(self):
-        for path, orig_stat in self._dependencies.items():
+        for path, orig_stat in listitems(self._dependencies):
             if not S_ISREG(orig_stat[ST_MODE]):
                 raise errors.StaleWriterStateError("{} not file".format(path))
             try:
@@ -474,6 +505,7 @@ class ResumableCollectionWriter(CollectionWriter):
 ADD = "add"
 DEL = "del"
 MOD = "mod"
+TOK = "tok"
 FILE = "file"
 COLLECTION = "collection"
 
@@ -487,7 +519,7 @@ class RichCollectionBase(CollectionBase):
 
     def __init__(self, parent=None):
         self.parent = parent
-        self._modified = True
+        self._committed = False
         self._callback = None
         self._items = {}
 
@@ -542,7 +574,7 @@ class RichCollectionBase(CollectionBase):
                     else:
                         item = ArvadosFile(self, pathcomponents[0])
                     self._items[pathcomponents[0]] = item
-                    self._modified = True
+                    self.set_committed(False)
                     self.notify(ADD, self, pathcomponents[0], item)
                 return item
             else:
@@ -550,12 +582,12 @@ class RichCollectionBase(CollectionBase):
                     # create new collection
                     item = Subcollection(self, pathcomponents[0])
                     self._items[pathcomponents[0]] = item
-                    self._modified = True
+                    self.set_committed(False)
                     self.notify(ADD, self, pathcomponents[0], item)
                 if isinstance(item, RichCollectionBase):
                     return item.find_or_create(pathcomponents[1], create_type)
                 else:
-                    raise IOError(errno.ENOTDIR, "Interior path components must be subcollection")
+                    raise IOError(errno.ENOTDIR, "Not a directory", pathcomponents[0])
         else:
             return self
 
@@ -563,16 +595,23 @@ class RichCollectionBase(CollectionBase):
     def find(self, path):
         """Recursively search the specified file path.
 
-        May return either a Collection or ArvadosFile.  Return None if not
+        May return either a Collection or ArvadosFile. Return None if not
         found.
+        If path is invalid (ex: starts with '/'), an IOError exception will be
+        raised.
 
         """
         if not path:
-            raise errors.ArgumentError("Parameter 'path' must not be empty.")
+            raise errors.ArgumentError("Parameter 'path' is empty.")
 
         pathcomponents = path.split("/", 1)
+        if pathcomponents[0] == '':
+            raise IOError(errno.ENOTDIR, "Not a directory", pathcomponents[0])
+
         item = self._items.get(pathcomponents[0])
-        if len(pathcomponents) == 1:
+        if item is None:
+            return None
+        elif len(pathcomponents) == 1:
             return item
         else:
             if isinstance(item, RichCollectionBase):
@@ -581,15 +620,20 @@ class RichCollectionBase(CollectionBase):
                 else:
                     return item
             else:
-                raise IOError(errno.ENOTDIR, "Interior path components must be subcollection")
+                raise IOError(errno.ENOTDIR, "Not a directory", pathcomponents[0])
 
+    @synchronized
     def mkdirs(self, path):
         """Recursive subcollection create.
 
-        Like `os.mkdirs()`.  Will create intermediate subcollections needed to
-        contain the leaf subcollection path.
+        Like `os.makedirs()`.  Will create intermediate subcollections needed
+        to contain the leaf subcollection path.
 
         """
+
+        if self.find(path) != None:
+            raise IOError(errno.EEXIST, "Directory or file exists", path)
+
         return self.find_or_create(path, COLLECTION)
 
     def open(self, path, mode="r"):
@@ -598,7 +642,12 @@ class RichCollectionBase(CollectionBase):
         :path:
           path to a file in the collection
         :mode:
-          one of "r", "r+", "w", "w+", "a", "a+"
+          a string consisting of "r", "w", or "a", optionally followed
+          by "b" or "t", optionally followed by "+".
+          :"b":
+            binary mode: write() accepts bytes, read() returns bytes.
+          :"t":
+            text mode (default): write() accepts strings, read() returns strings.
           :"r":
             opens for reading
           :"r+":
@@ -610,55 +659,61 @@ class RichCollectionBase(CollectionBase):
             the end of the file.  Writing does not affect the file pointer for
             reading.
         """
-        mode = mode.replace("b", "")
-        if len(mode) == 0 or mode[0] not in ("r", "w", "a"):
-            raise errors.ArgumentError("Bad mode '%s'" % mode)
-        create = (mode != "r")
 
-        if create and not self.writable():
-            raise IOError(errno.EROFS, "Collection is read only")
+        if not re.search(r'^[rwa][bt]?\+?$', mode):
+            raise errors.ArgumentError("Invalid mode {!r}".format(mode))
 
-        if create:
-            arvfile = self.find_or_create(path, FILE)
-        else:
+        if mode[0] == 'r' and '+' not in mode:
+            fclass = ArvadosFileReader
             arvfile = self.find(path)
+        elif not self.writable():
+            raise IOError(errno.EROFS, "Collection is read only")
+        else:
+            fclass = ArvadosFileWriter
+            arvfile = self.find_or_create(path, FILE)
 
         if arvfile is None:
-            raise IOError(errno.ENOENT, "File not found")
+            raise IOError(errno.ENOENT, "File not found", path)
         if not isinstance(arvfile, ArvadosFile):
-            raise IOError(errno.EISDIR, "Path must refer to a file.")
+            raise IOError(errno.EISDIR, "Is a directory", path)
 
-        if mode[0] == "w":
+        if mode[0] == 'w':
             arvfile.truncate(0)
 
-        name = os.path.basename(path)
+        return fclass(arvfile, mode=mode, num_retries=self.num_retries)
 
-        if mode == "r":
-            return ArvadosFileReader(arvfile, mode, num_retries=self.num_retries)
-        else:
-            return ArvadosFileWriter(arvfile, mode, num_retries=self.num_retries)
+    def modified(self):
+        """Determine if the collection has been modified since last commited."""
+        return not self.committed()
 
     @synchronized
-    def modified(self):
-        """Test if the collection (or any subcollection or file) has been modified."""
-        if self._modified:
-            return True
-        for k,v in self._items.items():
-            if v.modified():
-                return True
-        return False
+    def committed(self):
+        """Determine if the collection has been committed to the API server."""
+        return self._committed
 
     @synchronized
-    def set_unmodified(self):
-        """Recursively clear modified flag."""
-        self._modified = False
-        for k,v in self._items.items():
-            v.set_unmodified()
+    def set_committed(self, value=True):
+        """Recursively set committed flag.
+
+        If value is True, set committed to be True for this and all children.
+
+        If value is False, set committed to be False for this and all parents.
+        """
+        if value == self._committed:
+            return
+        if value:
+            for k,v in listitems(self._items):
+                v.set_committed(True)
+            self._committed = True
+        else:
+            self._committed = False
+            if self.parent is not None:
+                self.parent.set_committed(False)
 
     @synchronized
     def __iter__(self):
         """Iterate over names of files and collections contained in this collection."""
-        return iter(self._items.keys())
+        return iter(viewkeys(self._items))
 
     @synchronized
     def __getitem__(self, k):
@@ -684,7 +739,7 @@ class RichCollectionBase(CollectionBase):
     def __delitem__(self, p):
         """Delete an item by name which is directly contained by this collection."""
         del self._items[p]
-        self._modified = True
+        self.set_committed(False)
         self.notify(DEL, self, p, None)
 
     @synchronized
@@ -695,12 +750,12 @@ class RichCollectionBase(CollectionBase):
     @synchronized
     def values(self):
         """Get a list of files and collection objects directly contained in this collection."""
-        return self._items.values()
+        return listvalues(self._items)
 
     @synchronized
     def items(self):
         """Get a list of (name, object) tuples directly contained in this collection."""
-        return self._items.items()
+        return listitems(self._items)
 
     def exists(self, path):
         """Test if there is a file or collection at `path`."""
@@ -716,24 +771,24 @@ class RichCollectionBase(CollectionBase):
         """
 
         if not path:
-            raise errors.ArgumentError("Parameter 'path' must not be empty.")
+            raise errors.ArgumentError("Parameter 'path' is empty.")
 
         pathcomponents = path.split("/", 1)
         item = self._items.get(pathcomponents[0])
         if item is None:
-            raise IOError(errno.ENOENT, "File not found")
+            raise IOError(errno.ENOENT, "File not found", path)
         if len(pathcomponents) == 1:
             if isinstance(self._items[pathcomponents[0]], RichCollectionBase) and len(self._items[pathcomponents[0]]) > 0 and not recursive:
-                raise IOError(errno.ENOTEMPTY, "Subcollection not empty")
+                raise IOError(errno.ENOTEMPTY, "Directory not empty", path)
             deleteditem = self._items[pathcomponents[0]]
             del self._items[pathcomponents[0]]
-            self._modified = True
+            self.set_committed(False)
             self.notify(DEL, self, pathcomponents[0], deleteditem)
         else:
             item.remove(pathcomponents[1])
 
     def _clonefrom(self, source):
-        for k,v in source.items():
+        for k,v in listitems(source):
             self._items[k] = v.clone(self, k)
 
     def clone(self):
@@ -762,7 +817,7 @@ class RichCollectionBase(CollectionBase):
         """
 
         if target_name in self and not overwrite:
-            raise IOError(errno.EEXIST, "File already exists")
+            raise IOError(errno.EEXIST, "File already exists", target_name)
 
         modified_from = None
         if target_name in self:
@@ -770,13 +825,13 @@ class RichCollectionBase(CollectionBase):
 
         # Actually make the move or copy.
         if reparent:
-            source_obj.reparent(self, target_name)
+            source_obj._reparent(self, target_name)
             item = source_obj
         else:
             item = source_obj.clone(self, target_name)
 
         self._items[target_name] = item
-        self._modified = True
+        self.set_committed(False)
 
         if modified_from:
             self.notify(MOD, self, target_name, (modified_from, item))
@@ -791,7 +846,7 @@ class RichCollectionBase(CollectionBase):
         if isinstance(source, basestring):
             source_obj = source_collection.find(source)
             if source_obj is None:
-                raise IOError(errno.ENOENT, "File not found")
+                raise IOError(errno.ENOENT, "File not found", source)
             sourcecomponents = source.split("/")
         else:
             source_obj = source
@@ -815,9 +870,9 @@ class RichCollectionBase(CollectionBase):
                 target_dir = self
 
         if target_dir is None:
-            raise IOError(errno.ENOENT, "Target directory not found.")
+            raise IOError(errno.ENOENT, "Target directory not found", target_name)
 
-        if target_name in target_dir and isinstance(self[target_name], RichCollectionBase) and sourcecomponents:
+        if target_name in target_dir and isinstance(target_dir[target_name], RichCollectionBase) and sourcecomponents:
             target_dir = target_dir[target_name]
             target_name = sourcecomponents[-1]
 
@@ -870,7 +925,7 @@ class RichCollectionBase(CollectionBase):
 
         source_obj, target_dir, target_name = self._get_src_target(source, target_path, source_collection, False)
         if not source_obj.writable():
-            raise IOError(errno.EROFS, "Source collection must be writable.")
+            raise IOError(errno.EROFS, "Source collection is read only", source)
         target_dir.add(source_obj, target_name, overwrite, True)
 
     def portable_manifest_text(self, stream_name="."):
@@ -885,7 +940,9 @@ class RichCollectionBase(CollectionBase):
         """
         return self._get_manifest_text(stream_name, True, True)
 
-    def manifest_text(self, stream_name=".", strip=False, normalize=False):
+    @synchronized
+    def manifest_text(self, stream_name=".", strip=False, normalize=False,
+                      only_committed=False):
         """Get the manifest text for this collection, sub collections and files.
 
         This method will flush outstanding blocks to Keep.  By default, it will
@@ -904,13 +961,18 @@ class RichCollectionBase(CollectionBase):
           is not modified, return the original manifest text even if it is not
           in normalized form.
 
+        :only_committed:
+          If True, don't commit pending blocks.
+
         """
 
-        self._my_block_manager().commit_all()
-        return self._get_manifest_text(stream_name, strip, normalize)
+        if not only_committed:
+            self._my_block_manager().commit_all()
+        return self._get_manifest_text(stream_name, strip, normalize,
+                                       only_committed=only_committed)
 
     @synchronized
-    def _get_manifest_text(self, stream_name, strip, normalize):
+    def _get_manifest_text(self, stream_name, strip, normalize, only_committed=False):
         """Get the manifest text for this collection, sub collections and files.
 
         :stream_name:
@@ -926,9 +988,12 @@ class RichCollectionBase(CollectionBase):
           is not modified, return the original manifest text even if it is not
           in normalized form.
 
+        :only_committed:
+          If True, only include blocks that were already committed to Keep.
+
         """
 
-        if self.modified() or self._manifest_text is None or normalize:
+        if not self.committed() or self._manifest_text is None or normalize:
             stream = {}
             buf = []
             sorted_keys = sorted(self.keys())
@@ -939,6 +1004,8 @@ class RichCollectionBase(CollectionBase):
                 for segment in arvfile.segments():
                     loc = segment.locator
                     if arvfile.parent._my_block_manager().is_bufferblock(loc):
+                        if only_committed:
+                            continue
                         loc = arvfile.parent._my_block_manager().get_bufferblock(loc).locator()
                     if strip:
                         loc = KeepLocator(loc).stripped()
@@ -948,7 +1015,7 @@ class RichCollectionBase(CollectionBase):
             if stream:
                 buf.append(" ".join(normalize_stream(stream_name, stream)) + "\n")
             for dirname in [s for s in sorted_keys if isinstance(self[s], RichCollectionBase)]:
-                buf.append(self[dirname].manifest_text(stream_name=os.path.join(stream_name, dirname), strip=strip, normalize=True))
+                buf.append(self[dirname].manifest_text(stream_name=os.path.join(stream_name, dirname), strip=strip, normalize=True, only_committed=only_committed))
             return "".join(buf)
         else:
             if strip:
@@ -975,6 +1042,8 @@ class RichCollectionBase(CollectionBase):
                     changes.extend(self[k].diff(end_collection[k], os.path.join(prefix, k), holding_collection))
                 elif end_collection[k] != self[k]:
                     changes.append((MOD, os.path.join(prefix, k), self[k].clone(holding_collection, ""), end_collection[k].clone(holding_collection, "")))
+                else:
+                    changes.append((TOK, os.path.join(prefix, k), self[k].clone(holding_collection, ""), end_collection[k].clone(holding_collection, "")))
             else:
                 changes.append((ADD, os.path.join(prefix, k), end_collection[k].clone(holding_collection, "")))
         return changes
@@ -989,13 +1058,13 @@ class RichCollectionBase(CollectionBase):
 
         """
         if changes:
-            self._modified = True
+            self.set_committed(False)
         for change in changes:
             event_type = change[0]
             path = change[1]
             initial = change[2]
             local = self.find(path)
-            conflictpath = "%s~conflict-%s~" % (path, time.strftime("%Y-%m-%d-%H:%M:%S",
+            conflictpath = "%s~%s~conflict~" % (path, time.strftime("%Y%m%d-%H%M%S",
                                                                     time.gmtime()))
             if event_type == ADD:
                 if local is None:
@@ -1005,7 +1074,7 @@ class RichCollectionBase(CollectionBase):
                     # There is already local file and it is different:
                     # save change to conflict file.
                     self.copy(initial, conflictpath)
-            elif event_type == MOD:
+            elif event_type == MOD or event_type == TOK:
                 final = change[3]
                 if local == initial:
                     # Local matches the "initial" item so it has not
@@ -1030,8 +1099,13 @@ class RichCollectionBase(CollectionBase):
 
     def portable_data_hash(self):
         """Get the portable data hash for this collection's manifest."""
-        stripped = self.portable_manifest_text()
-        return hashlib.md5(stripped).hexdigest() + '+' + str(len(stripped))
+        if self._manifest_locator and self.committed():
+            # If the collection is already saved on the API server, and it's committed
+            # then return API server's PDH response.
+            return self._portable_data_hash
+        else:
+            stripped = self.portable_manifest_text().encode()
+            return '{}+{}'.format(hashlib.md5(stripped).hexdigest(), len(stripped))
 
     @synchronized
     def subscribe(self, callback):
@@ -1069,6 +1143,12 @@ class RichCollectionBase(CollectionBase):
     def __ne__(self, other):
         return not self.__eq__(other)
 
+    @synchronized
+    def flush(self):
+        """Flush bufferblocks to Keep."""
+        for e in listvalues(self):
+            e.flush()
+
 
 class Collection(RichCollectionBase):
     """Represents the root of an Arvados Collection.
@@ -1115,32 +1195,47 @@ class Collection(RichCollectionBase):
                  num_retries=None,
                  parent=None,
                  apiconfig=None,
-                 block_manager=None):
+                 block_manager=None,
+                 replication_desired=None,
+                 put_threads=None):
         """Collection constructor.
 
         :manifest_locator_or_text:
-          One of Arvados collection UUID, block locator of
-          a manifest, raw manifest text, or None (to create an empty collection).
+          An Arvados collection UUID, portable data hash, raw manifest
+          text, or (if creating an empty collection) None.
+
         :parent:
           the parent Collection, may be None.
+
         :apiconfig:
           A dict containing keys for ARVADOS_API_HOST and ARVADOS_API_TOKEN.
           Prefer this over supplying your own api_client and keep_client (except in testing).
           Will use default config settings if not specified.
+
         :api_client:
           The API client object to use for requests.  If not specified, create one using `apiconfig`.
+
         :keep_client:
           the Keep client to use for requests.  If not specified, create one using `apiconfig`.
+
         :num_retries:
           the number of retries for API and Keep requests.
+
         :block_manager:
           the block manager to use.  If not specified, create one.
 
+        :replication_desired:
+          How many copies should Arvados maintain. If None, API server default
+          configuration applies. If not None, this value will also be used
+          for determining the number of block copies being written.
+
         """
         super(Collection, self).__init__(parent)
         self._api_client = api_client
         self._keep_client = keep_client
         self._block_manager = block_manager
+        self.replication_desired = replication_desired
+        self.put_threads = put_threads
 
         if apiconfig:
             self._config = apiconfig
@@ -1150,21 +1245,23 @@ class Collection(RichCollectionBase):
         self.num_retries = num_retries if num_retries is not None else 0
         self._manifest_locator = None
         self._manifest_text = None
+        self._portable_data_hash = None
         self._api_response = None
+        self._past_versions = set()
 
         self.lock = threading.RLock()
         self.events = None
 
         if manifest_locator_or_text:
-            if re.match(util.keep_locator_pattern, manifest_locator_or_text):
+            if re.match(arvados.util.keep_locator_pattern, manifest_locator_or_text):
                 self._manifest_locator = manifest_locator_or_text
-            elif re.match(util.collection_uuid_pattern, manifest_locator_or_text):
+            elif re.match(arvados.util.collection_uuid_pattern, manifest_locator_or_text):
                 self._manifest_locator = manifest_locator_or_text
-            elif re.match(util.manifest_pattern, manifest_locator_or_text):
+            elif re.match(arvados.util.manifest_pattern, manifest_locator_or_text):
                 self._manifest_text = manifest_locator_or_text
             else:
                 raise errors.ArgumentError(
-                    "Argument to CollectionReader must be a manifest or a collection UUID")
+                    "Argument to CollectionReader is not a manifest or a collection UUID")
 
             try:
                 self._populate()
@@ -1174,12 +1271,28 @@ class Collection(RichCollectionBase):
     def root_collection(self):
         return self
 
+    def get_properties(self):
+        if self._api_response and self._api_response["properties"]:
+            return self._api_response["properties"]
+        else:
+            return {}
+
+    def get_trash_at(self):
+        if self._api_response and self._api_response["trash_at"]:
+            return ciso8601.parse_datetime(self._api_response["trash_at"])
+        else:
+            return None
+
     def stream_name(self):
         return "."
 
     def writable(self):
         return True
 
+    @synchronized
+    def known_past_version(self, modified_at_and_portable_data_hash):
+        return modified_at_and_portable_data_hash in self._past_versions
+
     @synchronized
     @retry_method
     def update(self, other=None, num_retries=None):
@@ -1189,6 +1302,15 @@ class Collection(RichCollectionBase):
             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)
+            if (self.known_past_version((response.get("modified_at"), response.get("portable_data_hash"))) and
+                response.get("portable_data_hash") != self.portable_data_hash()):
+                # The record on the server is different from our current one, but we've seen it before,
+                # so ignore it because it's already been merged.
+                # However, if it's the same as our current record, proceed with the update, because we want to update
+                # our tokens.
+                return
+            else:
+                self._past_versions.add((response.get("modified_at"), response.get("portable_data_hash")))
             other = CollectionReader(response["manifest_text"])
         baseline = CollectionReader(self._manifest_text)
         self.apply(baseline.diff(other))
@@ -1198,7 +1320,8 @@ class Collection(RichCollectionBase):
     def _my_api(self):
         if self._api_client is None:
             self._api_client = ThreadSafeApiCache(self._config)
-            self._keep_client = self._api_client.keep
+            if self._keep_client is None:
+                self._keep_client = self._api_client.keep
         return self._api_client
 
     @synchronized
@@ -1213,9 +1336,16 @@ class Collection(RichCollectionBase):
     @synchronized
     def _my_block_manager(self):
         if self._block_manager is None:
-            self._block_manager = _BlockManager(self._my_keep())
+            copies = (self.replication_desired or
+                      self._my_api()._rootDesc.get('defaultCollectionReplication',
+                                                   2))
+            self._block_manager = _BlockManager(self._my_keep(), copies=copies, put_threads=self.put_threads)
         return self._block_manager
 
+    def _remember_api_response(self, response):
+        self._api_response = response
+        self._past_versions.add((response.get("modified_at"), response.get("portable_data_hash")))
+
     def _populate_from_api_server(self):
         # As in KeepClient itself, we must wait until the last
         # possible moment to instantiate an API client, in order to
@@ -1224,62 +1354,27 @@ class Collection(RichCollectionBase):
         # it.  If instantiation fails, we'll fall back to the except
         # clause, just like any other Collection lookup
         # failure. Return an exception, or None if successful.
-        try:
-            self._api_response = self._my_api().collections().get(
-                uuid=self._manifest_locator).execute(
-                    num_retries=self.num_retries)
-            self._manifest_text = self._api_response['manifest_text']
-            return None
-        except Exception as e:
-            return e
-
-    def _populate_from_keep(self):
-        # Retrieve a manifest directly from Keep. This has a chance of
-        # working if [a] the locator includes a permission signature
-        # or [b] the Keep services are operating in world-readable
-        # mode. Return an exception, or None if successful.
-        try:
-            self._manifest_text = self._my_keep().get(
-                self._manifest_locator, num_retries=self.num_retries)
-        except Exception as e:
-            return e
+        self._remember_api_response(self._my_api().collections().get(
+            uuid=self._manifest_locator).execute(
+                num_retries=self.num_retries))
+        self._manifest_text = self._api_response['manifest_text']
+        self._portable_data_hash = self._api_response['portable_data_hash']
+        # If not overriden via kwargs, we should try to load the
+        # replication_desired from the API server
+        if self.replication_desired is None:
+            self.replication_desired = self._api_response.get('replication_desired', None)
 
     def _populate(self):
-        if self._manifest_locator is None and self._manifest_text is None:
-            return
-        error_via_api = None
-        error_via_keep = None
-        should_try_keep = ((self._manifest_text is None) and
-                           util.keep_locator_pattern.match(
-                               self._manifest_locator))
-        if ((self._manifest_text is None) and
-            util.signed_locator_pattern.match(self._manifest_locator)):
-            error_via_keep = self._populate_from_keep()
-        if self._manifest_text is None:
-            error_via_api = self._populate_from_api_server()
-            if error_via_api is not None and not should_try_keep:
-                raise error_via_api
-        if ((self._manifest_text is None) and
-            not error_via_keep and
-            should_try_keep):
-            # Looks like a keep locator, and we didn't already try keep above
-            error_via_keep = self._populate_from_keep()
         if self._manifest_text is None:
-            # Nothing worked!
-            raise errors.NotFoundError(
-                ("Failed to retrieve collection '{}' " +
-                 "from either API server ({}) or Keep ({})."
-                 ).format(
-                    self._manifest_locator,
-                    error_via_api,
-                    error_via_keep))
-        # populate
+            if self._manifest_locator is None:
+                return
+            else:
+                self._populate_from_api_server()
         self._baseline_manifest = self._manifest_text
         self._import_manifest(self._manifest_text)
 
-
     def _has_collection_uuid(self):
-        return self._manifest_locator is not None and re.match(util.collection_uuid_pattern, self._manifest_locator)
+        return self._manifest_locator is not None and re.match(arvados.util.collection_uuid_pattern, self._manifest_locator)
 
     def __enter__(self):
         return self
@@ -1289,6 +1384,9 @@ class Collection(RichCollectionBase):
         if exc_type is None:
             if self.writable() and self._has_collection_uuid():
                 self.save()
+        self.stop_threads()
+
+    def stop_threads(self):
         if self._block_manager is not None:
             self._block_manager.stop_threads()
 
@@ -1352,17 +1450,34 @@ class Collection(RichCollectionBase):
     @must_be_writable
     @synchronized
     @retry_method
-    def save(self, merge=True, num_retries=None):
+    def save(self,
+             properties=None,
+             storage_classes=None,
+             trash_at=None,
+             merge=True,
+             num_retries=None):
         """Save collection to an existing collection record.
 
         Commit pending buffer blocks to Keep, merge with remote record (if
-        merge=True, the default), and update the collection record.  Returns
+        merge=True, the default), and update the collection record. Returns
         the current manifest text.
 
         Will raise AssertionError if not associated with a collection record on
         the API server.  If you want to save a manifest to Keep only, see
         `save_new()`.
 
+        :properties:
+          Additional properties of collection. This value will replace any existing
+          properties of collection.
+
+        :storage_classes:
+          Specify desirable storage classes to be used when writing data to Keep.
+
+        :trash_at:
+          A collection is *expiring* when it has a *trash_at* time in the future.
+          An expiring collection can be accessed as normal,
+          but is scheduled to be trashed automatically at the *trash_at* time.
+
         :merge:
           Update and merge remote changes before saving.  Otherwise, any
           remote changes will be ignored and overwritten.
@@ -1371,9 +1486,27 @@ class Collection(RichCollectionBase):
           Retry count on API calls (if None,  use the collection default)
 
         """
-        if self.modified():
+        if properties and type(properties) is not dict:
+            raise errors.ArgumentError("properties must be dictionary type.")
+
+        if storage_classes and type(storage_classes) is not list:
+            raise errors.ArgumentError("storage_classes must be list type.")
+
+        if trash_at and type(trash_at) is not datetime.datetime:
+            raise errors.ArgumentError("trash_at must be datetime type.")
+
+        body={}
+        if properties:
+            body["properties"] = properties
+        if storage_classes:
+            body["storage_classes_desired"] = storage_classes
+        if trash_at:
+            t = trash_at.strftime("%Y-%m-%dT%H:%M:%S.%fZ")
+            body["trash_at"] = t
+
+        if not self.committed():
             if not self._has_collection_uuid():
-                raise AssertionError("Collection manifest_locator must be a collection uuid.  Use save_new() for new collections.")
+                raise AssertionError("Collection manifest_locator is not a collection uuid.  Use save_new() for new collections.")
 
             self._my_block_manager().commit_all()
 
@@ -1381,13 +1514,20 @@ class Collection(RichCollectionBase):
                 self.update()
 
             text = self.manifest_text(strip=False)
-            self._api_response = self._my_api().collections().update(
+            body['manifest_text'] = text
+
+            self._remember_api_response(self._my_api().collections().update(
                 uuid=self._manifest_locator,
-                body={'manifest_text': text}
-                ).execute(
-                    num_retries=num_retries)
+                body=body
+                ).execute(num_retries=num_retries))
             self._manifest_text = self._api_response["manifest_text"]
-            self.set_unmodified()
+            self._portable_data_hash = self._api_response["portable_data_hash"]
+            self.set_committed(True)
+        elif body:
+            self._remember_api_response(self._my_api().collections().update(
+                uuid=self._manifest_locator,
+                body=body
+                ).execute(num_retries=num_retries))
 
         return self._manifest_text
 
@@ -1398,6 +1538,9 @@ class Collection(RichCollectionBase):
     def save_new(self, name=None,
                  create_collection_record=True,
                  owner_uuid=None,
+                 properties=None,
+                 storage_classes=None,
+                 trash_at=None,
                  ensure_unique_name=False,
                  num_retries=None):
         """Save collection to a new collection record.
@@ -1405,7 +1548,7 @@ class Collection(RichCollectionBase):
         Commit pending buffer blocks to Keep and, when create_collection_record
         is True (default), create a new collection record.  After creating a
         new collection record, this Collection object will be associated with
-        the new record used by `save()`.  Returns the current manifest text.
+        the new record used by `save()`. Returns the current manifest text.
 
         :name:
           The collection name.
@@ -1418,6 +1561,18 @@ class Collection(RichCollectionBase):
           the user, or project uuid that will own this collection.
           If None, defaults to the current user.
 
+        :properties:
+          Additional properties of collection. This value will replace any existing
+          properties of collection.
+
+        :storage_classes:
+          Specify desirable storage classes to be used when writing data to Keep.
+
+        :trash_at:
+          A collection is *expiring* when it has a *trash_at* time in the future.
+          An expiring collection can be accessed as normal,
+          but is scheduled to be trashed automatically at the *trash_at* time.
+
         :ensure_unique_name:
           If True, ask the API server to rename the collection
           if it conflicts with a collection with the same name and owner.  If
@@ -1427,29 +1582,51 @@ class Collection(RichCollectionBase):
           Retry count on API calls (if None,  use the collection default)
 
         """
+        if properties and type(properties) is not dict:
+            raise errors.ArgumentError("properties must be dictionary type.")
+
+        if storage_classes and type(storage_classes) is not list:
+            raise errors.ArgumentError("storage_classes must be list type.")
+
+        if trash_at and type(trash_at) is not datetime.datetime:
+            raise errors.ArgumentError("trash_at must be datetime type.")
+
         self._my_block_manager().commit_all()
         text = self.manifest_text(strip=False)
 
         if create_collection_record:
             if name is None:
-                name = "Collection created %s" % (time.strftime("%Y-%m-%d %H:%M:%S %Z", time.localtime()))
+                name = "New collection"
                 ensure_unique_name = True
 
             body = {"manifest_text": text,
-                    "name": name}
+                    "name": name,
+                    "replication_desired": self.replication_desired}
             if owner_uuid:
                 body["owner_uuid"] = owner_uuid
-
-            self._api_response = self._my_api().collections().create(ensure_unique_name=ensure_unique_name, body=body).execute(num_retries=num_retries)
+            if properties:
+                body["properties"] = properties
+            if storage_classes:
+                body["storage_classes_desired"] = storage_classes
+            if trash_at:
+                t = trash_at.strftime("%Y-%m-%dT%H:%M:%S.%fZ")
+                body["trash_at"] = t
+
+            self._remember_api_response(self._my_api().collections().create(ensure_unique_name=ensure_unique_name, body=body).execute(num_retries=num_retries))
             text = self._api_response["manifest_text"]
 
             self._manifest_locator = self._api_response["uuid"]
+            self._portable_data_hash = self._api_response["portable_data_hash"]
 
             self._manifest_text = text
-            self.set_unmodified()
+            self.set_committed(True)
 
         return text
 
+    _token_re = re.compile(r'(\S+)(\s+|$)')
+    _block_re = re.compile(r'[0-9a-f]{32}\+(\d+)(\+\S+)*')
+    _segment_re = re.compile(r'(\d+):(\d+):(\S+)')
+
     @synchronized
     def _import_manifest(self, manifest_text):
         """Import a manifest into a `Collection`.
@@ -1468,7 +1645,7 @@ class Collection(RichCollectionBase):
         stream_name = None
         state = STREAM_NAME
 
-        for token_and_separator in re.finditer(r'(\S+)(\s+|$)', manifest_text):
+        for token_and_separator in self._token_re.finditer(manifest_text):
             tok = token_and_separator.group(1)
             sep = token_and_separator.group(2)
 
@@ -1477,25 +1654,25 @@ class Collection(RichCollectionBase):
                 stream_name = tok.replace('\\040', ' ')
                 blocks = []
                 segments = []
-                streamoffset = 0L
+                streamoffset = 0
                 state = BLOCKS
-                self.mkdirs(stream_name)
+                self.find_or_create(stream_name, COLLECTION)
                 continue
 
             if state == BLOCKS:
-                block_locator = re.match(r'[0-9a-f]{32}\+(\d+)(\+\S+)*', tok)
+                block_locator = self._block_re.match(tok)
                 if block_locator:
-                    blocksize = long(block_locator.group(1))
+                    blocksize = int(block_locator.group(1))
                     blocks.append(Range(tok, streamoffset, blocksize, 0))
                     streamoffset += blocksize
                 else:
                     state = SEGMENTS
 
             if state == SEGMENTS:
-                file_segment = re.search(r'^(\d+):(\d+):(\S+)', tok)
+                file_segment = self._segment_re.match(tok)
                 if file_segment:
-                    pos = long(file_segment.group(1))
-                    size = long(file_segment.group(2))
+                    pos = int(file_segment.group(1))
+                    size = int(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)
@@ -1505,13 +1682,13 @@ class Collection(RichCollectionBase):
                         raise errors.SyntaxError("File %s conflicts with stream of the same name.", filepath)
                 else:
                     # error!
-                    raise errors.SyntaxError("Invalid manifest format")
+                    raise errors.SyntaxError("Invalid manifest format, expected file segment but did not match format: '%s'" % tok)
 
             if sep == "\n":
                 stream_name = None
                 state = STREAM_NAME
 
-        self.set_unmodified()
+        self.set_committed(True)
 
     @synchronized
     def notify(self, event, collection, name, item):
@@ -1523,7 +1700,7 @@ class Subcollection(RichCollectionBase):
     """This is a subdirectory within a collection that doesn't have its own API
     server record.
 
-    It falls under the umbrella of the root collection.
+    Subcollection locking falls under the umbrella lock of its root collection.
 
     """
 
@@ -1560,21 +1737,20 @@ class Subcollection(RichCollectionBase):
 
     @must_be_writable
     @synchronized
-    def reparent(self, newparent, newname):
-        # XXX add flush()
+    def _reparent(self, newparent, newname):
+        self.set_committed(False)
+        self.flush()
         self.parent.remove(self.name, recursive=True)
         self.parent = newparent
         self.name = newname
         self.lock = self.parent.root_collection().lock
-        self._modified = True
 
 
 class CollectionReader(Collection):
     """A read-only collection object.
 
-    Initialize from an api collection record locator, a portable data hash of a
-    manifest, or raw manifest text.  See `Collection` constructor for detailed
-    options.
+    Initialize from a collection UUID or portable data hash, or raw
+    manifest text.  See `Collection` constructor for detailed options.
 
     """
     def __init__(self, manifest_locator_or_text, *args, **kwargs):