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1 # 2 # Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 The SCons Foundation 3 # 4 # Permission is hereby granted, free of charge, to any person obtaining 5 # a copy of this software and associated documentation files (the 6 # "Software"), to deal in the Software without restriction, including 7 # without limitation the rights to use, copy, modify, merge, publish, 8 # distribute, sublicense, and/or sell copies of the Software, and to 9 # permit persons to whom the Software is furnished to do so, subject to 10 # the following conditions: 11 # 12 # The above copyright notice and this permission notice shall be included 13 # in all copies or substantial portions of the Software. 14 # 15 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY 16 # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE 17 # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 18 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 19 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 20 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 21 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 22 # 23 24 __revision__ = "src/engine/SCons/CacheDir.py 4720 2010/03/24 03:14:11 jars" 25 26 __doc__ = """ 27 CacheDir support 28 """ 29 30 import os.path 31 import stat 32 import string 33 import sys 34 35 import SCons.Action 36 37 cache_enabled = True 38 cache_debug = False 39 cache_force = False 40 cache_show = False 4143 t = target[0] 44 fs = t.fs 45 cd = env.get_CacheDir() 46 cachedir, cachefile = cd.cachepath(t) 47 if not fs.exists(cachefile): 48 cd.CacheDebug('CacheRetrieve(%s): %s not in cache\n', t, cachefile) 49 return 1 50 cd.CacheDebug('CacheRetrieve(%s): retrieving from %s\n', t, cachefile) 51 if SCons.Action.execute_actions: 52 if fs.islink(cachefile): 53 fs.symlink(fs.readlink(cachefile), t.path) 54 else: 55 env.copy_from_cache(cachefile, t.path) 56 st = fs.stat(cachefile) 57 fs.chmod(t.path, stat.S_IMODE(st[stat.ST_MODE]) | stat.S_IWRITE) 58 return 05961 t = target[0] 62 fs = t.fs 63 cd = env.get_CacheDir() 64 cachedir, cachefile = cd.cachepath(t) 65 if t.fs.exists(cachefile): 66 return "Retrieved `%s' from cache" % t.path 67 return None68 69 CacheRetrieve = SCons.Action.Action(CacheRetrieveFunc, CacheRetrieveString) 70 71 CacheRetrieveSilent = SCons.Action.Action(CacheRetrieveFunc, None) 7274 t = target[0] 75 if t.nocache: 76 return 77 fs = t.fs 78 cd = env.get_CacheDir() 79 cachedir, cachefile = cd.cachepath(t) 80 if fs.exists(cachefile): 81 # Don't bother copying it if it's already there. Note that 82 # usually this "shouldn't happen" because if the file already 83 # existed in cache, we'd have retrieved the file from there, 84 # not built it. This can happen, though, in a race, if some 85 # other person running the same build pushes their copy to 86 # the cache after we decide we need to build it but before our 87 # build completes. 88 cd.CacheDebug('CachePush(%s): %s already exists in cache\n', t, cachefile) 89 return 90 91 cd.CacheDebug('CachePush(%s): pushing to %s\n', t, cachefile) 92 93 tempfile = cachefile+'.tmp'+str(os.getpid()) 94 errfmt = "Unable to copy %s to cache. Cache file is %s" 95 96 if not fs.isdir(cachedir): 97 try: 98 fs.makedirs(cachedir) 99 except EnvironmentError: 100 # We may have received an exception because another process 101 # has beaten us creating the directory. 102 if not fs.isdir(cachedir): 103 msg = errfmt % (str(target), cachefile) 104 raise SCons.Errors.EnvironmentError, msg 105 106 try: 107 if fs.islink(t.path): 108 fs.symlink(fs.readlink(t.path), tempfile) 109 else: 110 fs.copy2(t.path, tempfile) 111 fs.rename(tempfile, cachefile) 112 st = fs.stat(t.path) 113 fs.chmod(cachefile, stat.S_IMODE(st[stat.ST_MODE]) | stat.S_IWRITE) 114 except EnvironmentError: 115 # It's possible someone else tried writing the file at the 116 # same time we did, or else that there was some problem like 117 # the CacheDir being on a separate file system that's full. 118 # In any case, inability to push a file to cache doesn't affect 119 # the correctness of the build, so just print a warning. 120 msg = errfmt % (str(target), cachefile) 121 SCons.Warnings.warn(SCons.Warnings.CacheWriteErrorWarning, msg)122 123 CachePush = SCons.Action.Action(CachePushFunc, None) 124126212 213 # Local Variables: 214 # tab-width:4 215 # indent-tabs-mode:nil 216 # End: 217 # vim: set expandtab tabstop=4 shiftwidth=4: 218128 try: 129 import hashlib 130 except ImportError: 131 msg = "No hashlib or MD5 module available, CacheDir() not supported" 132 SCons.Warnings.warn(SCons.Warnings.NoMD5ModuleWarning, msg) 133 self.path = None 134 else: 135 self.path = path 136 self.current_cache_debug = None 137 self.debugFP = None138140 if cache_debug != self.current_cache_debug: 141 if cache_debug == '-': 142 self.debugFP = sys.stdout 143 elif cache_debug: 144 self.debugFP = open(cache_debug, 'w') 145 else: 146 self.debugFP = None 147 self.current_cache_debug = cache_debug 148 if self.debugFP: 149 self.debugFP.write(fmt % (target, os.path.split(cachefile)[1]))150 153155 """ 156 """ 157 if not self.is_enabled(): 158 return None, None 159 160 sig = node.get_cachedir_bsig() 161 subdir = string.upper(sig[0]) 162 dir = os.path.join(self.path, subdir) 163 return dir, os.path.join(dir, sig)164166 """ 167 This method is called from multiple threads in a parallel build, 168 so only do thread safe stuff here. Do thread unsafe stuff in 169 built(). 170 171 Note that there's a special trick here with the execute flag 172 (one that's not normally done for other actions). Basically 173 if the user requested a no_exec (-n) build, then 174 SCons.Action.execute_actions is set to 0 and when any action 175 is called, it does its showing but then just returns zero 176 instead of actually calling the action execution operation. 177 The problem for caching is that if the file does NOT exist in 178 cache then the CacheRetrieveString won't return anything to 179 show for the task, but the Action.__call__ won't call 180 CacheRetrieveFunc; instead it just returns zero, which makes 181 the code below think that the file *was* successfully 182 retrieved from the cache, therefore it doesn't do any 183 subsequent building. However, the CacheRetrieveString didn't 184 print anything because it didn't actually exist in the cache, 185 and no more build actions will be performed, so the user just 186 sees nothing. The fix is to tell Action.__call__ to always 187 execute the CacheRetrieveFunc and then have the latter 188 explicitly check SCons.Action.execute_actions itself. 189 """ 190 if not self.is_enabled(): 191 return False 192 193 env = node.get_build_env() 194 if cache_show: 195 if CacheRetrieveSilent(node, [], env, execute=1) == 0: 196 node.build(presub=0, execute=0) 197 return True 198 else: 199 if CacheRetrieve(node, [], env, execute=1) == 0: 200 return True 201 202 return False203 208
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