Add option to truncate long string literals.

2 files changed, 38 insertions, 0 deletions

diff --git a/sqlparse/filters.py b/sqlparse/filters.py
index 70f1051..337d3bf 100644
--- a/sqlparse/filters.py
+++ b/sqlparse/filters.py
@@ -47,6 +47,27 @@ class IdentifierCaseFilter(_CaseFilter):
             yield ttype, value
 
 
+class TruncateStringFilter:
+
+    def __init__(self, width, char):
+        self.width = max(width, 1)
+        self.char = unicode(char)
+
+    def process(self, stack, stream):
+        for ttype, value in stream:
+            if ttype is T.Literal.String.Single:
+                if value[:2] == '\'\'':
+                    inner = value[2:-2]
+                    quote = u'\'\''
+                else:
+                    inner = value[1:-1]
+                    quote = u'\''
+                if len(inner) > self.width:
+                    value = u''.join((quote, inner[:self.width], self.char,
+                                      quote))
+            yield ttype, value
+
+
 class GetComments:
     """Get the comments from a stack"""
     def process(self, stack, stream):
diff --git a/sqlparse/formatter.py b/sqlparse/formatter.py
index 8761c16..811f5af 100644
--- a/sqlparse/formatter.py
+++ b/sqlparse/formatter.py
@@ -33,6 +33,19 @@ def validate_options(options):
         raise SQLParseError('Invalid value for strip_whitespace: %r'
                             % strip_ws)
 
+    truncate_strings = options.get('truncate_strings', None)
+    if truncate_strings is not None:
+        try:
+            truncate_strings = int(truncate_strings)
+        except (ValueError, TypeError):
+            raise SQLParseError('Invalid value for truncate_strings: %r'
+                                % truncate_strings)
+        if truncate_strings <= 1:
+            raise SQLParseError('Invalid value for truncate_strings: %r'
+                                % truncate_strings)
+        options['truncate_strings'] = truncate_strings
+        options['truncate_char'] = options.get('truncate_char', '[...]')
+
     reindent = options.get('reindent', False)
     if reindent not in [True, False]:
         raise SQLParseError('Invalid value for reindent: %r'
@@ -84,6 +97,10 @@ def build_filter_stack(stack, options):
         stack.preprocess.append(
             filters.IdentifierCaseFilter(options['identifier_case']))
 
+    if options.get('truncate_strings', None) is not None:
+        stack.preprocess.append(filters.TruncateStringFilter(
+            width=options['truncate_strings'], char=options['truncate_char']))
+
     # After grouping
     if options.get('strip_comments', False):
         stack.enable_grouping()