Merge pull request aeron-io#227 from mmcilroy/master

var length data support for python

Author: mjpt777

main/java/uk/co/real_logic/sbe/generation/python/PythonGenerator.java

@@ -26,6 +26,7 @@
 
 import java.io.IOException;
 import java.io.Writer;
+import java.nio.ByteOrder;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -333,56 +334,49 @@ private CharSequence generateVarData(final List<Token> tokens)
  final String characterEncoding = tokens.get(i + 3).encoding().characterEncoding();
  final Token lengthToken = tokens.get(i + 2);
  final Integer sizeOfLengthField = Integer.valueOf(lengthToken.size());
- final String lengthCpp98Type = pythonTypeName(
- lengthToken.encoding().primitiveType(), lengthToken.encoding().byteOrder());
+ final String lengthPythonType = pythonTypeName(lengthToken.encoding().primitiveType(), lengthToken.encoding().byteOrder());
+
+ String byteOrder = ( lengthToken.encoding().byteOrder() == ByteOrder.BIG_ENDIAN ) ? ">" : "<";
 
  generateFieldMetaAttributeMethod(sb, token, BASE_INDENT);
 
  generateVarDataDescriptors(
- sb, token, propertyName, characterEncoding, lengthToken, sizeOfLengthField, lengthCpp98Type);
-
- /*
- * hmmm....
+ sb, token, propertyName, characterEncoding, lengthToken, sizeOfLengthField, lengthPythonType);
 
  sb.append(String.format(
  " def get%1$s(self):\n" +
  " sizeOfLengthField = %3$d\n" +
- " lengthPosition = position()\n" +
- " position(lengthPosition + sizeOfLengthField);\n" +
-
- " dataLength = struct.unpack_from('%5$s', self.buffer_, lengthPosition())[0]\n" +
- " int bytesToCopy = (length < dataLength) ? length : dataLength;\n" +
- " sbe_uint64_t pos = position();\n" +
- " position(position() + (sbe_uint64_t)dataLength);\n" +
- " ::memcpy(dst, buffer_ + pos, bytesToCopy);\n" +
- " return bytesToCopy;\n" +
- " }\n\n",
+ " lengthPosition = self.getPosition()\n" +
+ " dataLength = struct.unpack_from('%5$s', self.buffer_, lengthPosition[0])[0]\n" +
+ " self.setPosition(lengthPosition[0] + sizeOfLengthField)\n" +
+ " pos = self.getPosition()\n" +
+ " fmt = '" + byteOrder + "'+str(dataLength)+'c'\n" +
+ " data = struct.unpack_from(fmt, self.buffer_, lengthPosition[0])\n" +
+ " self.setPosition(pos[0] + dataLength)\n" +
+ " return data\n\n",
  propertyName,
  generateArrayFieldNotPresentCondition(token.version(), BASE_INDENT),
  sizeOfLengthField,
  formatByteOrderEncoding(lengthToken.encoding().byteOrder(), lengthToken.encoding().primitiveType()),
- lengthCpp98Type
+ lengthPythonType
  ));
 
- /*
  sb.append(String.format(
- " int set%1$s(const char *src, const int length)\n" +
- " {\n" +
- " sbe_uint64_t sizeOfLengthField = %2$d;\n" +
- " sbe_uint64_t lengthPosition = position();\n" +
- " *((%3$s *)(buffer_ + lengthPosition)) = %4$s((%3$s)length);\n" +
- " position(lengthPosition + sizeOfLengthField);\n" +
- " sbe_uint64_t pos = position();\n" +
- " position(position() + (sbe_uint64_t)length);\n" +
- " ::memcpy(buffer_ + pos, src, length);\n" +
- " return length;\n" +
- " }\n",
+ " def set%1$s(self, buffer):\n" +
+ " sizeOfLengthField = %2$d\n" +
+ " lengthPosition = self.getPosition()\n" +
+ " struct.pack_into('%3$s', self.buffer_, lengthPosition[0], len(buffer))\n" +
+ " self.setPosition(lengthPosition[0] + sizeOfLengthField)\n" +
+ " pos = self.getPosition()\n" +
+ " fmt = '" + byteOrder + "c'\n" +
+ " for i in range(0,len(buffer)):\n" +
+ " struct.pack_into(fmt, self.buffer_, lengthPosition[0]+i, buffer[i])\n" +
+ " self.setPosition(pos[0] + len(buffer))\n\n",
  propertyName,
  sizeOfLengthField,
- lengthCpp98Type,
+ lengthPythonType,
  formatByteOrderEncoding(lengthToken.encoding().byteOrder(), lengthToken.encoding().primitiveType())
  ));
- */
  }
  }
 
@@ -949,8 +943,8 @@ private CharSequence generateMessageFlyweightCode(final Token token)
  " self.buffer_ = buffer\n" +
  " self.offset_ = offset\n" +
  " self.bufferLength_ = bufferLength\n" +
- " self.actingBlockLength_ = sbeBlockLength()\n" +
- " self.actingVersion_ = sbeSchemaVersion()\n" +
+ " self.actingBlockLength_ = self.sbeBlockLength()\n" +
+ " self.actingVersion_ = self.sbeSchemaVersion()\n" +
  " self.setPosition(offset + self.actingBlockLength_)\n" +
  " return self\n\n" +