[pypy-commit] pypy framestate: Decode the bytecode up-front

[rlamy]

Author: Ronan Lamy <ronan.lamy at gmail.com>
Branch: framestate
Changeset: r74674:272d69dae528
Date: 2014-05-05 01:33 +0100
http://bitbucket.org/pypy/pypy/changeset/272d69dae528/

Log:	Decode the bytecode up-front

diff --git a/rpython/flowspace/bytecode.py b/rpython/flowspace/bytecode.py
--- a/rpython/flowspace/bytecode.py
+++ b/rpython/flowspace/bytecode.py
@@ -56,6 +56,7 @@
         self.co_firstlineno = firstlineno
         self.co_lnotab = lnotab
         self.signature = cpython_code_signature(self)
+        self.build_flow()
 
     def disassemble(self):
         contents = []
@@ -73,6 +74,14 @@
             i += 1
         return contents, offsets, jumps
 
+    def build_flow(self):
+        next_pos = pos = 0
+        contents, offsets, jumps = self.disassemble()
+        self.contents = zip(offsets, contents)
+        self.pos_index = dict((offset, i) for i, offset in enumerate(offsets))
+        # add end marker
+        self.contents.append((len(self.co_code), None))
+
 
     @classmethod
     def _from_code(cls, code):
@@ -95,6 +104,12 @@
         return bool(self.co_flags & CO_GENERATOR)
 
     def read(self, offset):
+        i = self.pos_index[offset]
+        op = self.contents[i][1]
+        next_offset = self.contents[i+1][0]
+        return next_offset, op
+
+    def decode(self, offset):
         return bc_reader.read(self, offset)
 
 class BytecodeReader(object):