upstream/mercurial-mirror Files · mercurial/node.py

revlog: make compressed size comparisons consistent...

revlog: make compressed size comparisons consistent revlog.compress() compares the compressed size to the input size and throws away the compressed data if it is larger than the input. This is the correct thing to do, as storing compressed data that is larger than the input takes up more storage space and makes reading slower. However, the comparison was implemented inconsistently. For the streaming compression mode, we threw away the result if it was greater than or equal to the input size. But for the one-shot compression, we threw away the compression only if it was greater than the input size! This patch changes the comparison for the simple case so it is consistent with the streaming case. As a few tests demonstrate, this adds 1 byte to some revlog entries. This is because of an added 'u' header on the chunk. It seems somewhat wrong to increase the revlog size here. However, IMO the cost of 1 byte in storage is insignificant compared to the performance gains of avoiding decompression. This patch should invite questions around the heuristic for throwing away compressed data. For example, I'd argue we should be more liberal about rejecting compressed data, additionally doing so where the number of bytes saved fails to reach a threshold. But we can have this discussion another time.

Durham Goode - - Load All Authors

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        Martin Geisler
    
put license and copyright info into comment blocks

              r8226
            
      # node.py - basic nodeid manipulation for mercurial

      #

      # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>

      #

      # This software may be used and distributed according to the terms of the

        Matt Mackall
    
Update license to GPLv2+

              r10263
            
      # GNU General Public License version 2 or any later version.

        mpm@selenic.com
    
Break apart hg.py...

              r1089
            
        Gregory Szorc
    
node: use absolute_import

              r25962
            
      from __future__ import absolute_import

        Matt Mackall
    
Replace demandload with new demandimport

              r3877
            
      import binascii

        mpm@selenic.com
    
Break apart hg.py...

              r1089
            
        Siddharth Agarwal
    
node: add 'nullhex', hex-encoded nullid...

              r26980
            
      # This ugly style has a noticeable effect in manifest parsing

      hex = binascii.hexlify

      bin = binascii.unhexlify

        Thomas Arendsen Hein
    
Define and use nullrev (revision of nullid) instead of -1.

              r3578
            
      nullrev = -1

        Gregory Szorc
    
node: use byte literals to construct nullid and wdirid...

              r28585
            
      nullid = b"\0" * 20

        Siddharth Agarwal
    
node: add 'nullhex', hex-encoded nullid...

              r26980
            
      nullhex = hex(nullid)

        mpm@selenic.com
    
Break apart hg.py...

              r1089
            
        Durham Goode
    
dirstate: change placeholder hash length to 20 bytes...

              r30360
            
      # Phony node value to stand-in for new files in some uses of

      # manifests.

      newnodeid = '!' * 20

        Durham Goode
    
dirstate: change added/modified placeholder hash length to 20 bytes...

              r30361
            
      addednodeid = ('0' * 15) + 'added'

      modifiednodeid = ('0' * 12) + 'modified'

        Durham Goode
    
dirstate: change placeholder hash length to 20 bytes...

              r30360
            
        Durham Goode
    
dirstate: change added/modified placeholder hash length to 20 bytes...

              r30361
            
      wdirnodes = set((newnodeid, addednodeid, modifiednodeid))

        Durham Goode
    
dirstate: change placeholder hash length to 20 bytes...

              r30360
            
        Yuya Nishihara
    
node: define experimental identifiers for working directory...

              r25737
            
      # pseudo identifiers for working directory

      # (they are experimental, so don't add too many dependencies on them)

      wdirrev = 0x7fffffff

        Gregory Szorc
    
node: use byte literals to construct nullid and wdirid...

              r28585
            
      wdirid = b"\xff" * 20

        Yuya Nishihara
    
node: define experimental identifiers for working directory...

              r25737
            
        mpm@selenic.com
    
Break apart hg.py...

              r1089
            
      def short(node):

          return hex(node[:6])

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Martin Geisler put license and copyright info into comment blocks	r8226	# node.py - basic nodeid manipulation for mercurial
		#
		# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
		#
		# This software may be used and distributed according to the terms of the
Matt Mackall Update license to GPLv2+	r10263	# GNU General Public License version 2 or any later version.
mpm@selenic.com Break apart hg.py...	r1089
Gregory Szorc node: use absolute_import	r25962	from __future__ import absolute_import

Matt Mackall Replace demandload with new demandimport	r3877	import binascii
mpm@selenic.com Break apart hg.py...	r1089
Siddharth Agarwal node: add 'nullhex', hex-encoded nullid...	r26980	# This ugly style has a noticeable effect in manifest parsing
		hex = binascii.hexlify
		bin = binascii.unhexlify

Thomas Arendsen Hein Define and use nullrev (revision of nullid) instead of -1.	r3578	nullrev = -1
Gregory Szorc node: use byte literals to construct nullid and wdirid...	r28585	nullid = b"\0" * 20
Siddharth Agarwal node: add 'nullhex', hex-encoded nullid...	r26980	nullhex = hex(nullid)
mpm@selenic.com Break apart hg.py...	r1089
Durham Goode dirstate: change placeholder hash length to 20 bytes...	r30360	# Phony node value to stand-in for new files in some uses of
		# manifests.
		newnodeid = '!' * 20
Durham Goode dirstate: change added/modified placeholder hash length to 20 bytes...	r30361	addednodeid = ('0' * 15) + 'added'
		modifiednodeid = ('0' * 12) + 'modified'
Durham Goode dirstate: change placeholder hash length to 20 bytes...	r30360
Durham Goode dirstate: change added/modified placeholder hash length to 20 bytes...	r30361	wdirnodes = set((newnodeid, addednodeid, modifiednodeid))
Durham Goode dirstate: change placeholder hash length to 20 bytes...	r30360
Yuya Nishihara node: define experimental identifiers for working directory...	r25737	# pseudo identifiers for working directory
		# (they are experimental, so don't add too many dependencies on them)
		wdirrev = 0x7fffffff
Gregory Szorc node: use byte literals to construct nullid and wdirid...	r28585	wdirid = b"\xff" * 20
Yuya Nishihara node: define experimental identifiers for working directory...	r25737
mpm@selenic.com Break apart hg.py...	r1089	def short(node):
		return hex(node[:6])