org.python.core

Interface ContainsPyBytecode

public interface ContainsPyBytecode

Jython stores Python bytecode of methods and functions that exceed JVM method size restrictions in string literals. While Java supports rather long strings, constrained only by int-addressing of arrays, it supports only up to 65535 characters in literals (not sure how escape-sequences are counted). To circumvent this limitation, the code is automatically split into several literals with the following naming-scheme.

The marker-interface ContainsPyBytecode indicates that a class contains (static final) literals of the following scheme:

• a prefix of '___' indicates a bytecode-containing string literal
• a number indicating the number of parts follows
• '0_' indicates that no splitting occurred
• otherwise another number follows, naming the index of the literal
• indexing starts at 0

Examples:

• ___0_method1 contains bytecode for method1
• ___2_0_method2 contains first part of method2's bytecode
• ___2_1_method2 contains second part of method2's bytecode

Note that this approach is provisional. In future, Jython might contain the bytecode directly as bytecode objects. The current approach was feasible with much less complicated JVM bytecode manipulation, but needs special treatment after class loading.

In a future approach this interface might be removed.

See Also:

BytecodeLoader.fixPyBytecode(Class)