Use constants for field/flag types

Avoids typos, such as one I just found which was 'strsng' isntead of
'string'. The static analyzer can catch those if they are constants.
Comparing ints is also faster than strings, which adds up in readmeta.

fdroidserver/lint.py

@@ -108,7 +108,7 @@ def check_regexes(app):
         for m, r in checks:
             v = app.get_field(f)
             t = metadata.metafieldtype(f)
-            if t == 'multiline':
+            if t == metadata.TYPE_MULTILINE:
                 for l in v.splitlines():
                     if m.match(l):
                         yield "%s at line '%s': %s" % (f, l, r)

fdroidserver/metadata.py

@@ -202,21 +202,31 @@ class App():
             else:
                 self.set_field(f, v)
 
+TYPE_UNKNOWN = 0
+TYPE_OBSOLETE = 1
+TYPE_STRING = 2
+TYPE_BOOL = 3
+TYPE_LIST = 4
+TYPE_SCRIPT = 5
+TYPE_MULTILINE = 6
+TYPE_BUILD = 7
+TYPE_BUILD_V2 = 8
+
 
 def metafieldtype(name):
     if name in ['Description', 'Maintainer Notes']:
-        return 'multiline'
+        return TYPE_MULTILINE
     if name in ['Categories', 'AntiFeatures']:
-        return 'list'
+        return TYPE_LIST
     if name == 'Build Version':
-        return 'build'
+        return TYPE_BUILD
     if name == 'Build':
-        return 'buildv2'
+        return TYPE_BUILD_V2
     if name == 'Use Built':
-        return 'obsolete'
+        return TYPE_OBSOLETE
     if name in app_fields:
-        return 'string'
+        return TYPE_STRING
-    return 'unknown'
+    return TYPE_UNKNOWN
 
 
 # In the order in which they are laid out on files
@@ -342,12 +352,12 @@ bool_flags = set(['submodules', 'oldsdkloc', 'forceversion', 'forcevercode',
 
 def flagtype(name):
     if name in list_flags:
-        return 'list'
+        return TYPE_LIST
     if name in script_flags:
-        return 'script'
+        return TYPE_SCRIPT
     if name in bool_flags:
-        return 'bool'
+        return TYPE_BOOL
-    return 'string'
+    return TYPE_STRING
 
 
 # Designates a metadata field type and checks that it matches
@@ -822,13 +832,13 @@ def post_metadata_parse(app):
                 continue
             ftype = flagtype(k)
 
-            if ftype == 'script':
+            if ftype == TYPE_SCRIPT:
                 build.__dict__[k] = re.sub(esc_newlines, '', v).lstrip().rstrip()
-            elif ftype == 'bool':
+            elif ftype == TYPE_BOOL:
                 # TODO handle this using <xsd:element type="xsd:boolean> in a schema
                 if isinstance(v, basestring) and v == 'true':
                     build.__dict__[k] = True
-            elif ftype == 'string':
+            elif ftype == TYPE_BOOL:
                 if isinstance(v, bool) and v:
                     build.__dict__[k] = 'yes'
 
@@ -1004,12 +1014,12 @@ def parse_txt_metadata(metadatapath):
         pk, pv = bv
         pk = pk.lstrip()
         t = flagtype(pk)
-        if t == 'list':
+        if t == TYPE_LIST:
             pv = split_list_values(pv)
             build.set_flag(pk, pv)
-        elif t == 'string' or t == 'script':
+        elif t == TYPE_STRING or t == TYPE_SCRIPT:
             build.set_flag(pk, pv)
-        elif t == 'bool':
+        elif t == TYPE_BOOL:
             if pv == 'yes':
                 build.set_flag(pk, True)
 
@@ -1099,17 +1109,17 @@ def parse_txt_metadata(metadatapath):
                 f = 'Current Version Code'
 
             ftype = metafieldtype(f)
-            if ftype not in ['build', 'buildv2']:
+            if ftype not in [TYPE_BUILD, TYPE_BUILD_V2]:
                 add_comments(f)
-            if ftype == 'multiline':
+            if ftype == TYPE_MULTILINE:
                 mode = 1
                 if v:
                     raise MetaDataException("Unexpected text on same line as " + f + " in " + linedesc)
-            elif ftype == 'string':
+            elif ftype == TYPE_STRING:
                 app.set_field(f, v)
-            elif ftype == 'list':
+            elif ftype == TYPE_LIST:
                 app.set_field(f, split_list_values(v))
-            elif ftype == 'build':
+            elif ftype == TYPE_BUILD:
                 if v.endswith("\\"):
                     mode = 2
                     del buildlines[:]
@@ -1118,7 +1128,7 @@ def parse_txt_metadata(metadatapath):
                     build = parse_buildline([v])
                     app.builds.append(build)
                     add_comments('build:' + app.builds[-1].vercode)
-            elif ftype == 'buildv2':
+            elif ftype == TYPE_BUILD_V2:
                 build = Build()
                 vv = v.split(',')
                 if len(vv) != 2:
@@ -1132,7 +1142,7 @@ def parse_txt_metadata(metadatapath):
                 vc_seen[build.vercode] = True
                 del buildlines[:]
                 mode = 3
-            elif ftype == 'obsolete':
+            elif ftype == TYPE_OBSOLETE:
                 pass        # Just throw it away!
             else:
                 raise MetaDataException("Unrecognised field type for " + f + " in " + linedesc)
@@ -1257,9 +1267,9 @@ def write_txt_metadata(mf, app):
 
     def w_field(f, v):
         t = metafieldtype(f)
-        if t == 'list':
+        if t == TYPE_LIST:
             v = ','.join(v)
-        elif t == 'multiline':
+        elif t == TYPE_MULTILINE:
             v = '\n' + v + '\n.'
         mf.write("%s:%s\n" % (f, v))
 
@@ -1273,13 +1283,13 @@ def write_txt_metadata(mf, app):
 
             t = flagtype(f)
             out = '    %s=' % f
-            if t == 'string':
+            if t == TYPE_STRING:
                 out += v
-            elif t == 'bool':
+            elif t == TYPE_BOOL:
                 out += 'yes'
-            elif t == 'script':
+            elif t == TYPE_SCRIPT:
                 out += '&& \\\n        '.join([s.lstrip() for s in v.split('&& ')])
-            elif t == 'list':
+            elif t == TYPE_LIST:
                 out += ','.join(v) if type(v) == list else v
 
             mf.write(out)
@@ -1304,20 +1314,20 @@ def write_yaml_metadata(mf, app):
         if t is None:
             t = metafieldtype(f)
         v = ''
-        if t == 'list':
+        if t == TYPE_LIST:
             v = '\n'
             for e in v:
                 v += prefix + ' - ' + escape(e) + '\n'
-        elif t == 'multiline':
+        elif t == TYPE_MULTILINE:
             v = ' |\n'
             for l in v.splitlines():
                 if l:
                     v += prefix + '  ' + l + '\n'
                 else:
                     v += '\n'
-        elif t == 'bool':
+        elif t == TYPE_BOOL:
             v = ' yes\n'
-        elif t == 'script':
+        elif t == TYPE_SCRIPT:
             cmds = [s + '&& \\' for s in v.split('&& ')]
             if len(cmds) > 0:
                 cmds[-1] = cmds[-1][:-len('&& \\')]
@@ -1340,8 +1350,8 @@ def write_yaml_metadata(mf, app):
             mf.write("builds:\n")
             first_build = False
 
-        w_field('versionName', build.version, '  - ', 'string')
+        w_field('versionName', build.version, '  - ', TYPE_STRING)
-        w_field('versionCode', build.vercode, '    ', 'strsng')
+        w_field('versionCode', build.vercode, '    ', TYPE_STRING)
         for f in build_flags_order:
             v = build.get_flag(f)
             if not v: