aboutsummaryrefslogtreecommitdiff
path: root/tools/cache.py
blob: c316a1fda3b24fc2ecaf5104063b349f74f34ed7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
import os.path, sys, shutil, hashlib, cPickle, zlib, time

import tempfiles

# Permanent cache for dlmalloc and stdlibc++
class Cache:
  def __init__(self, dirname=None, debug=False):
    if dirname is None:
      dirname = os.environ.get('EM_CACHE')
    if not dirname:
      dirname = os.path.expanduser(os.path.join('~', '.emscripten_cache'))
    self.dirname = dirname
    self.debug = debug

  def ensure(self):
    if not os.path.exists(self.dirname):
      os.makedirs(self.dirname)

  def erase(self):
    tempfiles.try_delete(self.dirname)
    try:
      open(self.dirname + '__last_clear', 'w').write('last clear: ' + time.asctime() + '\n')
    except Exception, e:
      print >> sys.stderr, 'failed to save last clear time: ', e

  def get_path(self, shortname):
    return os.path.join(self.dirname, shortname)

  # Request a cached file. If it isn't in the cache, it will be created with
  # the given creator function
  def get(self, shortname, creator, extension='.bc'):
    if not shortname.endswith(extension): shortname += extension
    cachename = os.path.join(self.dirname, shortname)
    if os.path.exists(cachename):
      return cachename
    self.ensure()
    shutil.copyfile(creator(), cachename)
    return cachename

# JS-specific cache. We cache the results of compilation and optimization,
# so that in incremental builds we can just load from cache.
# We cache reasonably-large-sized chunks
class JCache:
  def __init__(self, cache):
    self.cache = cache
    self.dirname = os.path.join(cache.dirname, 'jcache')
    self.debug = cache.debug

  def ensure(self):
    self.cache.ensure()
    if not os.path.exists(self.dirname):
      try:
        os.makedirs(self.dirname)
      except (IOError, OSError):
        pass

  def get_shortkey(self, keys):
    if type(keys) not in [list, tuple]:
      keys = [keys]
    ret = ''
    for key in keys:
      assert type(key) == str
      ret += hashlib.md5(key).hexdigest()
    return ret

  def get_cachename(self, shortkey):
    return os.path.join(self.dirname, shortkey)

  # Returns a cached value, if it exists. Make sure the full key matches
  def get(self, shortkey, keys):
    if self.debug: print >> sys.stderr, 'jcache get?', shortkey
    cachename = self.get_cachename(shortkey)
    if not os.path.exists(cachename):
      if self.debug: print >> sys.stderr, 'jcache none at all'
      return
    try:
      data = cPickle.loads(zlib.decompress(open(cachename).read()))
    except Exception, e:
      if self.debug: print >> sys.stderr, 'jcache decompress/unpickle error:', e
      return
    if len(data) != 2:
      if self.debug: print >> sys.stderr, 'jcache error in get'
      return
    oldkeys = data[0]
    if len(oldkeys) != len(keys):
      if self.debug: print >> sys.stderr, 'jcache collision (a)'
      return
    for i in range(len(oldkeys)):
      if oldkeys[i] != keys[i]:
        if self.debug: print >> sys.stderr, 'jcache collision (b)'
        return
    if self.debug: print >> sys.stderr, 'jcache win'
    return data[1]

  # Sets the cached value for a key (from get_key)
  def set(self, shortkey, keys, value):
    cachename = self.get_cachename(shortkey)
    try:
      f = open(cachename, 'w')
      f.write(zlib.compress(cPickle.dumps([keys, value])))
      f.close()
    except Exception, e:
      if self.debug: print >> sys.stderr, 'jcache compress/pickle error:', e
      return
    #  for i in range(len(keys)):
    #    open(cachename + '.key' + str(i), 'w').write(keys[i])
    #  open(cachename + '.value', 'w').write(value)

# Given a set of functions of form (ident, text), and a preferred chunk size,
# generates a set of chunks for parallel processing and caching.
# It is very important to generate similar chunks in incremental builds, in
# order to maximize the chance of cache hits. To achieve that, we save the
# chunking used in the previous compilation of this phase, and we try to
# generate the same chunks, barring big differences in function sizes that
# violate our chunk size guideline. If caching is not used, chunking_file
# should be None
def chunkify(funcs, chunk_size, chunking_file, DEBUG=False):
  previous_mapping = None
  if chunking_file:
    chunking_file = chunking_file
    if os.path.exists(chunking_file):
      try:
        previous_mapping = cPickle.Unpickler(open(chunking_file, 'rb')).load() # maps a function identifier to the chunk number it will be in
        #if DEBUG: print >> sys.stderr, 'jscache previous mapping', previous_mapping
      except:
        pass
  chunks = []
  if previous_mapping:
    # initialize with previous chunking
    news = []
    for func in funcs:
      ident, data = func
      assert ident, 'need names for jcache chunking'
      if not ident in previous_mapping:
        news.append(func)
      else:
        n = previous_mapping[ident]
        while n >= len(chunks): chunks.append([])
        chunks[n].append(func)
    if DEBUG: print >> sys.stderr, 'jscache not in previous chunking', len(news)
    # add news and adjust for new sizes
    spilled = news
    for i in range(len(chunks)):
      chunk = chunks[i]
      size = sum([len(func[1]) for func in chunk])
      #if DEBUG: print >> sys.stderr, 'need spilling?', i, size, len(chunk), 'vs', chunk_size, 1.5*chunk_size
      while size > 1.5*chunk_size and len(chunk) > 1:
        spill = chunk.pop()
        spilled.append(spill)
        size -= len(spill[1])
    #if DEBUG: print >> sys.stderr, 'jscache new + spilled', len(spilled)
    for chunk in chunks:
      size = sum([len(func[1]) for func in chunk])
      while size < 0.66*chunk_size and len(spilled) > 0:
        spill = spilled.pop()
        chunk.append(spill)
        size += len(spill[1])
    chunks = filter(lambda chunk: len(chunk) > 0, chunks) # might have empty ones, eliminate them
    funcs = spilled # we will allocate these into chunks as if they were normal inputs
    #if DEBUG: print >> sys.stderr, 'leftover spills', len(spilled)
  # initialize reasonably, the rest of the funcs we need to split out
  curr = []
  total_size = 0
  for i in range(len(funcs)):
    func = funcs[i]
    curr_size = len(func[1])
    if total_size + curr_size < chunk_size:
      curr.append(func)
      total_size += curr_size
    else:
      chunks.append(curr)
      curr = [func]
      total_size = curr_size
  if curr:
    chunks.append(curr)
    curr = None
  if chunking_file:
    # sort within each chunk, to keep the order identical
    for chunk in chunks:
      chunk.sort(key=lambda func: func[0])
    # save new mapping info
    new_mapping = {}
    for i in range(len(chunks)):
      chunk = chunks[i]
      for ident, data in chunk:
        assert ident not in new_mapping, 'cannot have duplicate names in jcache chunking'
        new_mapping[ident] = i
    cPickle.Pickler(open(chunking_file, 'wb')).dump(new_mapping)
    #if DEBUG:
    #  for i in range(len(chunks)):
    #    chunk = chunks[i]
    #    print >> sys.stderr, 'final chunk', i, len(chunk)
    #  print >> sys.stderr, 'new mapping:', new_mapping
    #  if previous_mapping:
    #    for ident in set(previous_mapping.keys() + new_mapping.keys()):
    #      if previous_mapping.get(ident) != new_mapping.get(ident):
    #        print >> sys.stderr, 'mapping inconsistency', ident, previous_mapping.get(ident), new_mapping.get(ident)
  return [''.join([func[1] for func in chunk]) for chunk in chunks] # remove function names