Add get_format_from_string utility method

[dak.git] / daklib / srcformats.py

diff --git a/daklib/srcformats.py b/daklib/srcformats.py
index f3afb8dba8b65b04fceca139b79b906b214e3080..ade3c45388b6a32d2e27c27d15a4a33a11e98b5a 100644 (file)
--- a/daklib/srcformats.py
+++ b/daklib/srcformats.py
@@ -5,6 +5,19 @@ from dak_exceptions import UnknownFormatError
 
 srcformats = []
 
+def get_format_from_string(txt):
+    """
+    Returns the SourceFormat class that corresponds to the specified .changes
+    Format value. If the string does not match any class, UnknownFormatError
+    is raised.
+    """
+
+    for format in srcformats:
+        if format.re_format.match(txt):
+            return format
+
+    raise UnknownFormatError, "Unknown format %r" % txt
+
 def parse_format(txt):
     """
     Parse a .changes Format string into a tuple representation for easy
@@ -59,15 +72,12 @@ class SourceFormat(type):
 
     @classmethod
     def validate_format(cls, format, is_a_dsc=False, field='files'):
-        if is_a_dsc:
-            if format != (1,0) and \
-               format != (3,0,"quilt") and format != (3,0,"native"):
-                raise UnknownFormatError, repr(format)
-        else:
-            if (format < (1,5) or format > (1,8)):
-                raise UnknownFormatError, repr(format)
-            if field != "files" and format < (1,8):
-                raise UnknownFormatError, repr(format)
+        """
+        Raises UnknownFormatError if the specified format tuple is not valid for
+        this format (for example, the format (1, 0) is not valid for the
+        "3.0 (quilt)" format). Return value is undefined in all other cases.
+        """
+        pass
 
 class FormatOne(SourceFormat):
     __metaclass__ = SourceFormat
@@ -91,6 +101,19 @@ class FormatOne(SourceFormat):
         for msg in super(FormatOne, cls).reject_msgs(has):
             yield msg
 
+    @classmethod
+    def validate_format(cls, format, is_a_dsc=False, field='files'):
+        msg = "Invalid format %s definition: %r" % (cls.name, format)
+
+        if is_a_dsc:
+            if format != (1, 0):
+                raise UnknownFormatError, msg
+        else:
+            if (format < (1,5) or format > (1,8)):
+                raise UnknownFormatError, msg
+            if field != "files" and format < (1,8):
+                raise UnknownFormatError, msg
+
 class FormatThree(SourceFormat):
     __metaclass__ = SourceFormat
 
@@ -100,6 +123,12 @@ class FormatThree(SourceFormat):
     requires = ('native_tar',)
     disallowed = ('orig_tar', 'debian_diff', 'debian_tar', 'more_orig_tar')
 
+    @classmethod
+    def validate_format(cls, format, **kwargs):
+        if format != (3, 0, 'native'):
+            raise UnknownFormatError, "Invalid format %s definition: %r" % \
+                (cls.name, format)
+
 class FormatThreeQuilt(SourceFormat):
     __metaclass__ = SourceFormat
 
@@ -108,3 +137,9 @@ class FormatThreeQuilt(SourceFormat):
 
     requires = ('orig_tar', 'debian_tar')
     disallowed = ('debian_diff', 'native_tar')
+
+    @classmethod
+    def validate_format(cls, format, **kwargs):
+        if format != (3, 0, 'quilt'):
+            raise UnknownFormatError, "Invalid format %s definition: %r" % \
+                (cls.name, format)