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-rw-r--r--engine/SCons/CacheDir.py118
1 files changed, 97 insertions, 21 deletions
diff --git a/engine/SCons/CacheDir.py b/engine/SCons/CacheDir.py
index 81c74f0..c9e8ea7 100644
--- a/engine/SCons/CacheDir.py
+++ b/engine/SCons/CacheDir.py
@@ -21,7 +21,7 @@
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
-__revision__ = "src/engine/SCons/CacheDir.py a56bbd8c09fb219ab8a9673330ffcd55279219d0 2019-03-26 23:16:31 bdeegan"
+__revision__ = "src/engine/SCons/CacheDir.py e724ae812eb96f4858a132f5b8c769724744faf6 2019-07-21 00:04:47 bdeegan"
__doc__ = """
CacheDir support
@@ -35,6 +35,7 @@ import sys
import SCons.Action
import SCons.Warnings
+from SCons.Util import PY3
cache_enabled = True
cache_debug = False
@@ -46,10 +47,12 @@ def CacheRetrieveFunc(target, source, env):
t = target[0]
fs = t.fs
cd = env.get_CacheDir()
+ cd.requests += 1
cachedir, cachefile = cd.cachepath(t)
if not fs.exists(cachefile):
cd.CacheDebug('CacheRetrieve(%s): %s not in cache\n', t, cachefile)
return 1
+ cd.hits += 1
cd.CacheDebug('CacheRetrieve(%s): retrieving from %s\n', t, cachefile)
if SCons.Action.execute_actions:
if fs.islink(cachefile):
@@ -111,7 +114,7 @@ def CachePushFunc(target, source, env):
# has beaten us creating the directory.
if not fs.isdir(cachedir):
msg = errfmt % (str(target), cachefile)
- raise SCons.Errors.EnvironmentError(msg)
+ raise SCons.Errors.SConsEnvironmentError(msg)
try:
if fs.islink(t.get_internal_path()):
@@ -139,34 +142,97 @@ warned = dict()
class CacheDir(object):
def __init__(self, path):
+ """
+ Initialize a CacheDir object.
+
+ The cache configuration is stored in the object. It
+ is read from the config file in the supplied path if
+ one exists, if not the config file is created and
+ the default config is written, as well as saved in the object.
+ """
+ self.requests = 0
+ self.hits = 0
self.path = path
self.current_cache_debug = None
self.debugFP = None
self.config = dict()
if path is None:
return
- # See if there's a config file in the cache directory. If there is,
- # use it. If there isn't, and the directory exists and isn't empty,
- # produce a warning. If the directory doesn't exist or is empty,
- # write a config file.
+
+ if PY3:
+ self._readconfig3(path)
+ else:
+ self._readconfig2(path)
+
+
+ def _readconfig3(self, path):
+ """
+ Python3 version of reading the cache config.
+
+ If directory or config file do not exist, create. Take advantage
+ of Py3 capability in os.makedirs() and in file open(): just try
+ the operation and handle failure appropriately.
+
+ Omit the check for old cache format, assume that's old enough
+ there will be none of those left to worry about.
+
+ :param path: path to the cache directory
+ """
+ config_file = os.path.join(path, 'config')
+ try:
+ os.makedirs(path, exist_ok=True)
+ except FileExistsError:
+ pass
+ except OSError:
+ msg = "Failed to create cache directory " + path
+ raise SCons.Errors.EnvironmentError(msg)
+
+ try:
+ with open(config_file, 'x') as config:
+ self.config['prefix_len'] = 2
+ try:
+ json.dump(self.config, config)
+ except Exception:
+ msg = "Failed to write cache configuration for " + path
+ raise SCons.Errors.EnvironmentError(msg)
+ except FileExistsError:
+ try:
+ with open(config_file) as config:
+ self.config = json.load(config)
+ except ValueError:
+ msg = "Failed to read cache configuration for " + path
+ raise SCons.Errors.EnvironmentError(msg)
+
+
+ def _readconfig2(self, path):
+ """
+ Python2 version of reading cache config.
+
+ See if there is a config file in the cache directory. If there is,
+ use it. If there isn't, and the directory exists and isn't empty,
+ produce a warning. If the directory does not exist or is empty,
+ write a config file.
+
+ :param path: path to the cache directory
+ """
config_file = os.path.join(path, 'config')
if not os.path.exists(config_file):
- # A note: There is a race hazard here, if two processes start and
+ # A note: There is a race hazard here if two processes start and
# attempt to create the cache directory at the same time. However,
- # python doesn't really give you the option to do exclusive file
- # creation (it doesn't even give you the option to error on opening
- # an existing file for writing...). The ordering of events here
- # as an attempt to alleviate this, on the basis that it's a pretty
- # unlikely occurence (it'd require two builds with a brand new cache
+ # Python 2.x does not give you the option to do exclusive file
+ # creation (not even the option to error on opening an existing
+ # file for writing...). The ordering of events here is an attempt
+ # to alleviate this, on the basis that it's a pretty unlikely
+ # occurrence (would require two builds with a brand new cache
# directory)
- if os.path.isdir(path) and len(os.listdir(path)) != 0:
+ if os.path.isdir(path) and any(f != "config" for f in os.listdir(path)):
self.config['prefix_len'] = 1
# When building the project I was testing this on, the warning
# was output over 20 times. That seems excessive
global warned
if self.path not in warned:
msg = "Please upgrade your cache by running " +\
- " scons-configure-cache.py " + self.path
+ "scons-configure-cache.py " + self.path
SCons.Warnings.warn(SCons.Warnings.CacheVersionWarning, msg)
warned[self.path] = True
else:
@@ -177,24 +243,24 @@ class CacheDir(object):
# If someone else is trying to create the directory at
# the same time as me, bad things will happen
msg = "Failed to create cache directory " + path
- raise SCons.Errors.EnvironmentError(msg)
-
+ raise SCons.Errors.SConsEnvironmentError(msg)
+
self.config['prefix_len'] = 2
if not os.path.exists(config_file):
try:
with open(config_file, 'w') as config:
json.dump(self.config, config)
- except:
+ except Exception:
msg = "Failed to write cache configuration for " + path
- raise SCons.Errors.EnvironmentError(msg)
+ raise SCons.Errors.SConsEnvironmentError(msg)
else:
try:
with open(config_file) as config:
self.config = json.load(config)
except ValueError:
msg = "Failed to read cache configuration for " + path
- raise SCons.Errors.EnvironmentError(msg)
-
+ raise SCons.Errors.SConsEnvironmentError(msg)
+
def CacheDebug(self, fmt, target, cachefile):
if cache_debug != self.current_cache_debug:
@@ -207,9 +273,19 @@ class CacheDir(object):
self.current_cache_debug = cache_debug
if self.debugFP:
self.debugFP.write(fmt % (target, os.path.split(cachefile)[1]))
+ self.debugFP.write("requests: %d, hits: %d, misses: %d, hit rate: %.2f%%\n" %
+ (self.requests, self.hits, self.misses, self.hit_ratio))
+
+ @property
+ def hit_ratio(self):
+ return (100.0 * self.hits / self.requests if self.requests > 0 else 100)
+
+ @property
+ def misses(self):
+ return self.requests - self.hits
def is_enabled(self):
- return cache_enabled and not self.path is None
+ return cache_enabled and self.path is not None
def is_readonly(self):
return cache_readonly