Apply vsm's suggestion of keeping a table of "earliest revisions"

tools/get_archive.py

Index: tools/get_archive.py
===================================================================
--- tools/get_archive.py	(revision 11000)
+++ tools/get_archive.py	(working copy)
@@ -60,18 +60,21 @@
 SDK_PERMANENT = ('gs://dart-editor-archive-continuous/%(version_num)s/' + 
     'dartsdk-%(osname)s-32.zip')
 
+# Dictionary storing the earliest revision of each download we have stored.
+LAST_VALID = {'dartium': 4285, 'chromedriver': 7823, 'sdk': 9761, 'drt': 5342}
+
 sys.path.append(os.path.join(GSUTIL_DIR, 'boto'))
 import boto
 
 
-def execute_command(*cmd):
+def ExecuteCommand(*cmd):
   """Execute a command in a subprocess."""
   pipe = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
   output, error = pipe.communicate()
   return pipe.returncode, output
 
 
-def execute_command_visible(*cmd):
+def ExecuteCommandVisible(*cmd):
   """Execute a command in a subprocess, but show stdout/stderr."""
   result = subprocess.call(cmd, stdout=sys.stdout, stderr=sys.stderr,
                            stdin=sys.stdin)
@@ -79,15 +82,15 @@
     raise Exception('Execution of "%s" failed' % ' '.join(cmd))
 
 
-def gsutil(*cmd):
-  return execute_command('python', GSUTIL, *cmd)
+def Gsutil(*cmd):
+  return ExecuteCommand('python', GSUTIL, *cmd)
 
 
-def gsutil_visible(*cmd):
-  execute_command_visible('python', GSUTIL, *cmd)
+def GsutilVisible(*cmd):
+  ExecuteCommandVisible('python', GSUTIL, *cmd)
 
 
-def has_boto_config():
+def HasBotoConfig():
   """Returns true if boto config exists."""
 
   config_paths = boto.pyami.config.BotoConfigLocations
@@ -100,14 +103,14 @@
   return False
 
 
-def in_runhooks():
+def InRunhooks():
   '''True if this script was called by "gclient runhooks" or "gclient sync"'''
   return 'runhooks' in sys.argv
 
 
-def ensure_config():
+def EnsureConfig():
   # If ~/.boto doesn't exist, tell the user to run "gsutil config"
-  if not has_boto_config():
+  if not HasBotoConfig():
     print >>sys.stderr, '''
 *******************************************************************************
 * WARNING: Can't download DumpRenderTree! This is required to test client apps.
@@ -121,7 +124,7 @@
     sys.exit(1)
 
 
-def get_dartium_revision(name, directory, version_file, latest_pattern,
+def GetDartiumRevision(name, directory, version_file, latest_pattern,
     permanent_prefix, revision_num=None):
   """Get the latest binary that is stored in the dartium archive.
 
@@ -137,7 +140,7 @@
   """
   osdict = {'Darwin':'mac', 'Linux':'lucid64', 'Windows':'win'}
 
-  def find_permanent_url(out, osname, revision_num):
+  def FindPermanentUrl(out, osname, revision_num):
     output_lines = out.split()
     latest = output_lines[-1]
     if not revision_num:
@@ -151,7 +154,7 @@
       while not foundURL:
         # Test to ensure this URL exists because the dartium-archive builds can
         # have unusual numbering (a range of CL numbers) sometimes.
-        result, out = gsutil('ls', permanent_prefix % {'osname' : osname,
+        result, out = Gsutil('ls', permanent_prefix % {'osname' : osname,
             'num1': '*', 'num2': revision_num })
         if result == 0:
           # First try to find one with the the second number the same as the
@@ -162,13 +165,14 @@
           # Now try to find one with a nearby CL num.
           revision_num = int(revision_num) - 1
           if revision_num <= 0:
-            too_early_error()
+            TooEarlyError()
     return latest
     
-  get_from_gsutil(name, directory, version_file, latest_pattern, osdict, 
-                  find_permanent_url, revision_num)
+  GetFromGsutil(name, directory, version_file, latest_pattern, osdict, 
+                  FindPermanentUrl, revision_num)
 
-def get_sdk_revision(name, directory, version_file, latest_pattern,
+
+def GetSdkRevision(name, directory, version_file, latest_pattern,
     permanent_prefix, revision_num):
   """Get a revision of the SDK from the editor build archive.
 
@@ -181,12 +185,12 @@
     revision_num: the desired revision number, or None for the most recent
   """
   osdict = {'Darwin':'macos', 'Linux':'linux', 'Windows':'win32'}
-  def find_permanent_url(out, osname, not_used):
+  def FindPermanentUrl(out, osname, not_used):
     rev_num = revision_num
     if not rev_num:
       temp_file = tempfile.NamedTemporaryFile()
       temp_file_url = 'file://' + temp_file.name
-      gsutil('cp', latest_pattern % {'osname' : osname }, temp_file_url)
+      Gsutil('cp', latest_pattern % {'osname' : osname }, temp_file_url)
       temp_file.seek(0)
       version_info = temp_file.read()
       temp_file.close()
@@ -198,10 +202,11 @@
     latest = (permanent_prefix % { 'osname' : osname, 'version_num': rev_num})
     return latest
     
-  get_from_gsutil(name, directory, version_file, latest_pattern, osdict,
-                  find_permanent_url, revision_num)
+  GetFromGsutil(name, directory, version_file, latest_pattern, osdict,
+                  FindPermanentUrl, revision_num)
 
-def get_from_gsutil(name, directory, version_file, latest_pattern,
+
+def GetFromGsutil(name, directory, version_file, latest_pattern,
     os_name_dict, get_permanent_url, revision_num = ''):
   """Download and unzip the desired file from Google Storage.
     Args:
@@ -224,11 +229,11 @@
         '%s.') % (system, name)
     return 0
 
-  ensure_config()
+  EnsureConfig()
 
   # Query for the lastest version
   pattern = latest_pattern  % { 'osname' : osname }
-  result, out = gsutil('ls', pattern)
+  result, out = Gsutil('ls', pattern)
   if result == 0:
     # use permanent link instead, just in case the latest zip entry gets deleted
     # while we are downloading it.
@@ -243,7 +248,7 @@
   if os.path.exists(version_file):
     v = open(version_file, 'r').read()
     if v == latest:
-      if not in_runhooks():
+      if not InRunhooks():
         print name + ' is up to date.\nVersion: ' + latest
       return 0 # up to date
 
@@ -257,13 +262,13 @@
     temp_zip = os.path.join(temp_dir, 'drt.zip')
     temp_zip_url = 'file://' + temp_zip
     # It's nice to show download progress
-    gsutil_visible('cp', latest, temp_zip_url)
+    GsutilVisible('cp', latest, temp_zip_url)
 
     if platform.system() != 'Windows':
       # The Python zip utility does not preserve executable permissions, but
       # this does not seem to be a problem for Windows, which does not have a
       # built in zip utility. :-/
-      result, out = execute_command('unzip', temp_zip, '-d', temp_dir)
+      result, out = ExecuteCommand('unzip', temp_zip, '-d', temp_dir)
       if result != 0:
         raise Exception('Execution of "unzip %s -d %s" failed: %s' %
                         (temp_zip, temp_dir, str(out)))
@@ -288,7 +293,8 @@
   print 'Successfully downloaded to %s' % directory
   return 0
 
-def too_early_error():
+
+def TooEarlyError():
   """Quick shortcutting function, to return early if someone requests a revision
   that is smaller than the earliest stored. This saves us from doing repeated
   requests until we get down to 0."""
@@ -296,6 +302,7 @@
       'earliest revision stored.')
   sys.exit(1)
 
+
 def main():
   parser = optparse.OptionParser(usage='usage: %prog [options] download_name')
   parser.add_option('-r', '--revision', dest='revision',
@@ -304,27 +311,22 @@
                     action='store', default=None)
   args, positional = parser.parse_args()
 
+  if args.revision and int(args.revision) < LAST_VALID[positional[0]]:
+    return TooEarlyError()
+
   if positional[0] == 'dartium':
-    if args.revision and args.revision < 4285:
-      return too_early_error()
-    get_dartium_revision('Dartium', DARTIUM_DIR, DARTIUM_VERSION,
+    GetDartiumRevision('Dartium', DARTIUM_DIR, DARTIUM_VERSION,
                          DARTIUM_LATEST_PATTERN, DARTIUM_PERMANENT_PATTERN,
                          args.revision)
   elif positional[0] == 'chromedriver':
-    if args.revision and args.revision < 7823:
-      return too_early_error()
-    get_dartium_revision('chromedriver', CHROMEDRIVER_DIR, CHROMEDRIVER_VERSION,
+    GetDartiumRevision('chromedriver', CHROMEDRIVER_DIR, CHROMEDRIVER_VERSION,
                          CHROMEDRIVER_LATEST_PATTERN,
                          CHROMEDRIVER_PERMANENT_PATTERN, args.revision)
   elif positional[0] == 'sdk':
-    if args.revision and args.revision < 9761:
-      return too_early_error()
-    get_sdk_revision('sdk', SDK_DIR, SDK_VERSION, SDK_LATEST_PATTERN,
+    GetSdkRevision('sdk', SDK_DIR, SDK_VERSION, SDK_LATEST_PATTERN,
         SDK_PERMANENT, args.revision)
   elif positional[0] == 'drt':
-    if args.revision and args.revision < 5342:
-      return too_early_error()
-    get_dartium_revision('DumpRenderTree', DRT_DIR, DRT_VERSION,
+    GetDartiumRevision('DumpRenderTree', DRT_DIR, DRT_VERSION,
                          DRT_LATEST_PATTERN, DRT_PERMANENT_PATTERN,
                          args.revision)
   else: