2853: Merge branch 'master' into 2853-rendezvous
[arvados.git] / sdk / python / arvados / stream.py
index 84461b3e8c7f92f660f1bf704842ca53798f661f..c263dd871be9d663d4aceebbfaf18f07aecd71dc 100644 (file)
-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
 
-class StreamFileReader(object):
-    def __init__(self, stream, pos, size, name):
+LOCATOR = 0
+BLOCKSIZE = 1
+OFFSET = 2
+SEGMENTSIZE = 3
+
+def locators_and_ranges(data_locators, range_start, range_size, debug=False):
+    '''
+    Get blocks that are covered by the range
+    data_locators: list of [locator, block_size, block_start], assumes that blocks are in order and contigous
+    range_start: start of range
+    range_size: size of range
+    returns list of [block locator, blocksize, segment offset, segment size] that satisfies the range
+    '''
+    if range_size == 0:
+        return []
+    resp = []
+    range_start = long(range_start)
+    range_size = long(range_size)
+    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)
+    block_size = data_locators[i][BLOCKSIZE]
+    block_start = data_locators[i][OFFSET]
+    block_end = block_start + block_size
+    if debug: print '---'
+
+    # 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:
+            # must be out of range, fail
+            return []
+        if range_start > block_start:
+            lo = i
+        else:
+            hi = i
+        i = int((hi + lo) / 2)
+        if debug: print lo, i, hi
+        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
+        if debug:
+            print locator, "range_start", range_start, "block_start", block_start, "range_end", range_end, "block_end", block_end
+        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:
+            # range starts after this block ends, so go to next block
+            # 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:
+            # range starts in this block
+            resp.append([locator, block_size, range_start - block_start, block_end - range_start])
+        elif range_start < block_start and range_end > block_end:
+            # range starts in a previous block and extends to further blocks
+            resp.append([locator, block_size, 0L, block_size])
+        elif range_start < block_start and range_end <= block_end:
+            # range starts in a previous block and ends in this block
+            resp.append([locator, block_size, 0L, range_end - block_start])
+        block_start = block_end
+        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
+
+
+    def __init__(self, stream, segments, name):
+        super(StreamFileReader, self).__init__(self._NameAttribute(name), 'rb')
         self._stream = stream
-        self._pos = pos
-        self._size = size
-        self._name = name
-        self._filepos = 0
+        self.segments = segments
+        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)$', '', self._name)
-
-    def size(self):
-        return self._size
+        return re.sub('\.(bz2|gz)$', '', self.name)
 
     def stream_name(self):
         return self._stream.name()
 
-    def read(self, size, **kwargs):
-        self._stream.seek(self._pos + self._filepos)
-        data = self._stream.read(min(size, self._size - self._filepos))
+    @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):
+        return self._filepos
+
+    def size(self):
+        n = self.segments[-1]
+        return n[OFFSET] + n[BLOCKSIZE]
+
+    @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 = ''
+        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, **kwargs):
+    @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, **kwargs)
+            data = self.read(size, num_retries=num_retries)
             if data == '':
                 break
             yield data
 
-    def seek(self, pos):
-        self._filepos = pos
-
-    def bunzip2(self, size):
-        decompressor = bz2.BZ2Decompressor()
-        for chunk in self.readall(size):
-            data = decompressor.decompress(chunk)
-            if data and data != '':
-                yield 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]
 
-    def gunzip(self, size):
-        decompressor = zlib.decompressobj(16+zlib.MAX_WBITS)
-        for chunk in self.readall(size):
-            data = decompressor.decompress(decompressor.unconsumed_tail + chunk)
-            if data and data != '':
+    @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):
-        self._stream.seek(self._pos + self._filepos)
-        if re.search('\.bz2$', self._name):
-            return self.bunzip2(size)
-        elif re.search('\.gz$', self._name):
-            return self.gunzip(size)
+    @ArvadosFileBase._before_close
+    @retry_method
+    def readall_decompressed(self, size=2**20, num_retries=None):
+        self.seek(0)
+        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)
 
-    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 stream_offset(self):
-        return self._pos
+    @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 as_manifest(self):
-        if self.size() == 0:
-            return ("%s %s 0:0:%s\n"
-                    % (self._stream.name(), config.EMPTY_BLOCK_LOCATOR, self.name()))
-        return string.join(self._stream.tokens_for_range(self._pos, self._size),
-                           " ") + "\n"
+        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._current_datablock_data = None
-        self._current_datablock_pos = 0
-        self._current_datablock_index = -1
-        self._pos = 0L
 
+class StreamReader(object):
+    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', ' ')
-            elif re.search(r'^[0-9a-f]{32}(\+\S+)*$', tok):
-                self.data_locators += [tok]
-            elif re.search(r'^\d+:\d+:\S+', tok):
-                pos, size, name = tok.split(':',2)
-                self.files += [[long(pos), long(size), name.replace('\\040', ' ')]]
-            else:
-                raise errors.SyntaxError("Invalid manifest format")
-
-    def tokens(self):
-        return self._tokens
-
-    def tokens_for_range(self, range_start, range_size):
-        resp = [self._stream_name]
-        return_all_tokens = False
-        block_start = 0
-        token_bytes_skipped = 0
-        for locator in self.data_locators:
-            sizehint = re.search(r'\+(\d+)', locator)
-            if not sizehint:
-                return_all_tokens = True
-            if return_all_tokens:
-                resp += [locator]
-                next
-            blocksize = int(sizehint.group(0))
-            if range_start + range_size <= block_start:
-                break
-            if range_start < block_start + blocksize:
-                resp += [locator]
-            else:
-                token_bytes_skipped += blocksize
-            block_start += blocksize
-        for f in self.files:
-            if ((f[0] < range_start + range_size)
-                and
-                (f[0] + f[1] > range_start)
-                and
-                f[1] > 0):
-                resp += ["%d:%d:%s" % (f[0] - token_bytes_skipped, f[1], f[2])]
-        return resp
-
-    LOCATOR = 0
-    BLOCKSIZE = 1
-    CHUNKOFFSET = 2
-    CHUNKSIZE = 3
+                continue
 
-    def locators_and_ranges(self, range_start, range_size):
-        '''returns list of [block locator, blocksize, chunk offset, chunk size] that satisfies the range'''
-        resp = []
-        return_all_tokens = False
-        range_start = long(range_start)
-        range_size = long(range_size)
-        range_end = range_start + range_size
-        block_start = 0L
-        for locator in self.data_locators:
-            sizehint = re.search(r'[0-9a-f]{32}\+(\d+)', locator)
-            if not sizehint:
-                raise Exception("Manifest must include block sizes to be normalized")
-            block_size = long(sizehint.group(1))
-            block_end = block_start + block_size
-            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:
-                # range starts after this block ends, so go to next block
-                next
-            elif 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:
-                # range starts in this block
-                resp.append([locator, block_size, range_start - block_start, block_end - range_start])
-            elif range_start < block_start and range_end > block_end:
-                # range starts in a previous block and extends to further blocks
-                resp.append([locator, block_size, 0L, block_size])
-            elif range_start < block_start and range_end <= block_end:
-                # range starts in a previous block and ends in this block
-                resp.append([locator, block_size, 0L, range_end - block_start])
-            block_start = block_end
-        return resp
+            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])
+                streamoffset += blocksize
+                continue
+
+            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', ' ')
+                if name not in self._files:
+                    self._files[name] = StreamFileReader(self, [[pos, size, 0]], name)
+                else:
+                    n = self._files[name]
+                    n.segments.append([pos, size, n.size()])
+                continue
+
+            raise errors.SyntaxError("Invalid manifest format")
 
     def name(self):
         return self._stream_name
 
+    def files(self):
+        return self._files
+
     def all_files(self):
-        for f in self.files:
-            pos, size, name = f
-            yield StreamFileReader(self, pos, size, name)
-
-    def nextdatablock(self):
-        if self._current_datablock_index < 0:
-            self._current_datablock_pos = 0
-            self._current_datablock_index = 0
-        else:
-            self._current_datablock_pos += self.current_datablock_size()
-            self._current_datablock_index += 1
-        self._current_datablock_data = None
-
-    def current_datablock_data(self):
-        if self._current_datablock_data == None:
-            self._current_datablock_data = Keep.get(self.data_locators[self._current_datablock_index])
-        return self._current_datablock_data
-
-    def current_datablock_size(self):
-        if self._current_datablock_index < 0:
-            self.nextdatablock()
-        sizehint = re.search('\+(\d+)', self.data_locators[self._current_datablock_index])
-        if sizehint:
-            return int(sizehint.group(0))
-        return len(self.current_datablock_data())
-
-    def seek(self, pos):
-        """Set the position of the next read operation."""
-        self._pos = pos
-
-    def really_seek(self):
-        """Find and load the appropriate data block, so the byte at
-        _pos is in memory.
-        """
-        if self._pos == self._current_datablock_pos:
-            return True
-        if (self._current_datablock_pos != None and
-            self._pos >= self._current_datablock_pos and
-            self._pos <= self._current_datablock_pos + self.current_datablock_size()):
-            return True
-        if self._pos < self._current_datablock_pos:
-            self._current_datablock_index = -1
-            self.nextdatablock()
-        while (self._pos > self._current_datablock_pos and
-               self._pos > self._current_datablock_pos + self.current_datablock_size()):
-            self.nextdatablock()
-
-    def read(self, size):
-        """Read no more than size bytes -- but at least one byte,
-        unless _pos is already at the end of the stream.
-        """
+        return self._files.values()
+
+    def size(self):
+        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)
+
+    @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 ''
-        self.really_seek()
-        while self._pos >= self._current_datablock_pos + self.current_datablock_size():
-            self.nextdatablock()
-            if self._current_datablock_index >= len(self.data_locators):
-                return None
-        data = self.current_datablock_data()[self._pos - self._current_datablock_pos : self._pos - self._current_datablock_pos + size]
-        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'