2853: Merge branch 'master' into 2853-rendezvous
[arvados.git] / sdk / python / arvados / stream.py
index 7dd57368915c5b29c63f4f525bd890c8b22a280e..c263dd871be9d663d4aceebbfaf18f07aecd71dc 100644 (file)
@@ -1,23 +1,12 @@
-import gflags
-import httplib
-import httplib2
-import logging
+import bz2
+import collections
+import hashlib
 import os
-import pprint
-import sys
-import types
-import subprocess
-import json
-import UserDict
 import re
-import hashlib
-import string
-import bz2
 import zlib
-import fcntl
-import time
-import threading
 
+from .arvfile import ArvadosFileBase
+from arvados.retry import retry_method
 from keep import *
 import config
 import errors
@@ -43,6 +32,9 @@ def locators_and_ranges(data_locators, range_start, range_size, debug=False):
     range_end = range_start + range_size
     block_start = 0L
 
+    # range_start/block_start is the inclusive lower bound
+    # range_end/block_end is the exclusive upper bound
+
     hi = len(data_locators)
     lo = 0
     i = int((hi + lo) / 2)
@@ -50,9 +42,14 @@ def locators_and_ranges(data_locators, range_start, range_size, debug=False):
     block_start = data_locators[i][OFFSET]
     block_end = block_start + block_size
     if debug: print '---'
-    while not (range_start >= block_start and range_start <= block_end):
+
+    # perform a binary search for the first block
+    # assumes that all of the blocks are contigious, so range_start is guaranteed
+    # to either fall into the range of a block or be outside the block range entirely
+    while not (range_start >= block_start and range_start < block_end):
         if lo == i:
-            break
+            # must be out of range, fail
+            return []
         if range_start > block_start:
             lo = i
         else:
@@ -62,7 +59,7 @@ def locators_and_ranges(data_locators, range_start, range_size, debug=False):
         block_size = data_locators[i][BLOCKSIZE]
         block_start = data_locators[i][OFFSET]
         block_end = block_start + block_size
-    
+
     while i < len(data_locators):
         locator, block_size, block_start = data_locators[i]
         block_end = block_start + block_size
@@ -71,10 +68,13 @@ def locators_and_ranges(data_locators, range_start, range_size, debug=False):
         if range_end <= block_start:
             # range ends before this block starts, so don't look at any more locators
             break
-        if range_start >= block_end:
+
+        #if range_start >= block_end:
             # range starts after this block ends, so go to next block
-            next
-        elif range_start >= block_start and range_end <= block_end:
+            # we should always start at the first block due to the binary above, so this test is redundant
+            #next
+
+        if range_start >= block_start and range_end <= block_end:
             # range starts and ends in this block
             resp.append([locator, block_size, range_start - block_start, range_size])
         elif range_start >= block_start and range_end > block_end:
@@ -90,116 +90,190 @@ def locators_and_ranges(data_locators, range_start, range_size, debug=False):
         i += 1
     return resp
 
+def split(path):
+    """split(path) -> streamname, filename
+
+    Separate the stream name and file name in a /-separated stream path.
+    If no stream name is available, assume '.'.
+    """
+    try:
+        stream_name, file_name = path.rsplit('/', 1)
+    except ValueError:  # No / in string
+        stream_name, file_name = '.', path
+    return stream_name, file_name
+
+class StreamFileReader(ArvadosFileBase):
+    class _NameAttribute(str):
+        # The Python file API provides a plain .name attribute.
+        # Older SDK provided a name() method.
+        # This class provides both, for maximum compatibility.
+        def __call__(self):
+            return self
+
 
-class StreamFileReader(object):
     def __init__(self, stream, segments, name):
+        super(StreamFileReader, self).__init__(self._NameAttribute(name), 'rb')
         self._stream = stream
         self.segments = segments
-        self._name = name
         self._filepos = 0L
+        self.num_retries = stream.num_retries
+        self._readline_cache = (None, None)
 
-    def name(self):
-        return self._name
+    def __iter__(self):
+        while True:
+            data = self.readline()
+            if not data:
+                break
+            yield data
 
     def decompressed_name(self):
-        return re.sub('\.(bz2|gz)$', '', self._name)
+        return re.sub('\.(bz2|gz)$', '', self.name)
 
     def stream_name(self):
         return self._stream.name()
 
-    def seek(self, pos):
+    @ArvadosFileBase._before_close
+    def seek(self, pos, whence=os.SEEK_CUR):
+        if whence == os.SEEK_CUR:
+            pos += self._filepos
+        elif whence == os.SEEK_END:
+            pos += self.size()
         self._filepos = min(max(pos, 0L), self.size())
 
-    def tell(self, pos):
+    def tell(self):
         return self._filepos
 
     def size(self):
         n = self.segments[-1]
         return n[OFFSET] + n[BLOCKSIZE]
 
-    def read(self, size):
+    @ArvadosFileBase._before_close
+    @retry_method
+    def read(self, size, num_retries=None):
         """Read up to 'size' bytes from the stream, starting at the current file position"""
         if size == 0:
             return ''
 
         data = ''
-        for locator, blocksize, segmentoffset, segmentsize in locators_and_ranges(self.segments, self._filepos, size):
-            self._stream.seek(locator+segmentoffset)
-            data += self._stream.read(segmentsize)
-            self._filepos += len(data)
+        available_chunks = locators_and_ranges(self.segments, self._filepos, size)
+        if available_chunks:
+            locator, blocksize, segmentoffset, segmentsize = available_chunks[0]
+            data = self._stream.readfrom(locator+segmentoffset, segmentsize,
+                                         num_retries=num_retries)
+
+        self._filepos += len(data)
         return data
 
-    def readall(self, size=2**20):
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readfrom(self, start, size, num_retries=None):
+        """Read up to 'size' bytes from the stream, starting at 'start'"""
+        if size == 0:
+            return ''
+
+        data = []
+        for locator, blocksize, segmentoffset, segmentsize in locators_and_ranges(self.segments, start, size):
+            data.append(self._stream.readfrom(locator+segmentoffset, segmentsize,
+                                              num_retries=num_retries))
+        return ''.join(data)
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readall(self, size=2**20, num_retries=None):
         while True:
-            data = self.read(size)
+            data = self.read(size, num_retries=num_retries)
             if data == '':
                 break
             yield data
 
-    def bunzip2(self, size):
-        decompressor = bz2.BZ2Decompressor()
-        for segment in self.readall(size):
-            data = decompressor.decompress(segment)
-            if data and data != '':
-                yield data
-
-    def gunzip(self, size):
-        decompressor = zlib.decompressobj(16+zlib.MAX_WBITS)
-        for segment in self.readall(size):
-            data = decompressor.decompress(decompressor.unconsumed_tail + segment)
-            if data and data != '':
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readline(self, size=float('inf'), num_retries=None):
+        cache_pos, cache_data = self._readline_cache
+        if self.tell() == cache_pos:
+            data = [cache_data]
+        else:
+            data = ['']
+        data_size = len(data[-1])
+        while (data_size < size) and ('\n' not in data[-1]):
+            next_read = self.read(2 ** 20, num_retries=num_retries)
+            if not next_read:
+                break
+            data.append(next_read)
+            data_size += len(next_read)
+        data = ''.join(data)
+        try:
+            nextline_index = data.index('\n') + 1
+        except ValueError:
+            nextline_index = len(data)
+        nextline_index = min(nextline_index, size)
+        self._readline_cache = (self.tell(), data[nextline_index:])
+        return data[:nextline_index]
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def decompress(self, decompress, size, num_retries=None):
+        for segment in self.readall(size, num_retries):
+            data = decompress(segment)
+            if data:
                 yield data
 
-    def readall_decompressed(self, size=2**20):
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readall_decompressed(self, size=2**20, num_retries=None):
         self.seek(0)
-        if re.search('\.bz2$', self._name):
-            return self.bunzip2(size)
-        elif re.search('\.gz$', self._name):
-            return self.gunzip(size)
+        if self.name.endswith('.bz2'):
+            dc = bz2.BZ2Decompressor()
+            return self.decompress(dc.decompress, size,
+                                   num_retries=num_retries)
+        elif self.name.endswith('.gz'):
+            dc = zlib.decompressobj(16+zlib.MAX_WBITS)
+            return self.decompress(lambda segment: dc.decompress(dc.unconsumed_tail + segment),
+                                   size, num_retries=num_retries)
         else:
-            return self.readall(size)
+            return self.readall(size, num_retries=num_retries)
+
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readlines(self, sizehint=float('inf'), num_retries=None):
+        data = []
+        data_size = 0
+        for s in self.readall(num_retries=num_retries):
+            data.append(s)
+            data_size += len(s)
+            if data_size >= sizehint:
+                break
+        return ''.join(data).splitlines(True)
 
-    def readlines(self, decompress=True):
-        if decompress:
-            datasource = self.readall_decompressed()
-        else:
-            self._stream.seek(self._pos + self._filepos)
-            datasource = self.readall()
-        data = ''
-        for newdata in datasource:
-            data += newdata
-            sol = 0
-            while True:
-                eol = string.find(data, "\n", sol)
-                if eol < 0:
-                    break
-                yield data[sol:eol+1]
-                sol = eol+1
-            data = data[sol:]
-        if data != '':
-            yield data
+    def as_manifest(self):
+        manifest_text = ['.']
+        manifest_text.extend([d[LOCATOR] for d in self._stream._data_locators])
+        manifest_text.extend(["{}:{}:{}".format(seg[LOCATOR], seg[BLOCKSIZE], self.name().replace(' ', '\\040')) for seg in self.segments])
+        return arvados.CollectionReader(' '.join(manifest_text) + '\n').manifest_text(normalize=True)
 
 
 class StreamReader(object):
-    def __init__(self, tokens):
-        self._tokens = tokens
-        self._pos = 0L
-
+    def __init__(self, tokens, keep=None, debug=False, _empty=False,
+                 num_retries=0):
         self._stream_name = None
-        self.data_locators = []
-        self.files = {}
+        self._data_locators = []
+        self._files = collections.OrderedDict()
+        self._keep = keep
+        self.num_retries = num_retries
 
         streamoffset = 0L
 
-        for tok in self._tokens:
-            if self._stream_name == None:
+        # parse stream
+        for tok in tokens:
+            if debug: print 'tok', tok
+            if self._stream_name is None:
                 self._stream_name = tok.replace('\\040', ' ')
                 continue
 
             s = re.match(r'^[0-9a-f]{32}\+(\d+)(\+\S+)*$', tok)
             if s:
                 blocksize = long(s.group(1))
-                self.data_locators.append([tok, blocksize, streamoffset])
+                self._data_locators.append([tok, blocksize, streamoffset])
                 streamoffset += blocksize
                 continue
 
@@ -208,44 +282,52 @@ class StreamReader(object):
                 pos = long(s.group(1))
                 size = long(s.group(2))
                 name = s.group(3).replace('\\040', ' ')
-                if name not in self.files:
-                    self.files[name] = StreamFileReader(self, [[pos, size, 0]], name)
+                if name not in self._files:
+                    self._files[name] = StreamFileReader(self, [[pos, size, 0]], name)
                 else:
-                    n = self.files[name]
+                    n = self._files[name]
                     n.segments.append([pos, size, n.size()])
                 continue
 
             raise errors.SyntaxError("Invalid manifest format")
-            
-    def tokens(self):
-        return self._tokens
 
     def name(self):
         return self._stream_name
 
-    def all_files(self):
-        return self.files.values()
-
-    def seek(self, pos):
-        """Set the position of the next read operation."""
-        self._pos = pos
+    def files(self):
+        return self._files
 
-    def tell(self):
-        return self._pos
+    def all_files(self):
+        return self._files.values()
 
     def size(self):
-        n = self.data_locators[-1]
-        return n[self.OFFSET] + n[self.BLOCKSIZE]
+        n = self._data_locators[-1]
+        return n[OFFSET] + n[BLOCKSIZE]
 
     def locators_and_ranges(self, range_start, range_size):
-        return locators_and_ranges(self.data_locators, range_start, range_size)
+        return locators_and_ranges(self._data_locators, range_start, range_size)
 
-    def read(self, size):
-        """Read up to 'size' bytes from the stream, starting at the current file position"""
+    @retry_method
+    def readfrom(self, start, size, num_retries=None):
+        """Read up to 'size' bytes from the stream, starting at 'start'"""
         if size == 0:
             return ''
-        data = ''
-        for locator, blocksize, segmentoffset, segmentsize in locators_and_ranges(self.data_locators, self._pos, size):
-            data += Keep.get(locator)[segmentoffset:segmentoffset+segmentsize]
-        self._pos += len(data)
-        return data
+        if self._keep is None:
+            self._keep = KeepClient(num_retries=self.num_retries)
+        data = []
+        for locator, blocksize, segmentoffset, segmentsize in locators_and_ranges(self._data_locators, start, size):
+            data.append(self._keep.get(locator, num_retries=num_retries)[segmentoffset:segmentoffset+segmentsize])
+        return ''.join(data)
+
+    def manifest_text(self, strip=False):
+        manifest_text = [self.name().replace(' ', '\\040')]
+        if strip:
+            for d in self._data_locators:
+                m = re.match(r'^[0-9a-f]{32}\+\d+', d[LOCATOR])
+                manifest_text.append(m.group(0))
+        else:
+            manifest_text.extend([d[LOCATOR] for d in self._data_locators])
+        manifest_text.extend([' '.join(["{}:{}:{}".format(seg[LOCATOR], seg[BLOCKSIZE], f.name().replace(' ', '\\040'))
+                                        for seg in f.segments])
+                              for f in self._files.values()])
+        return ' '.join(manifest_text) + '\n'