rewrite functions in pyrex for performance

on my machine;
* n64_fast.crc is 29 times faster
* Yaz0_fast.decode is 226 times faster

Yaz0.py

@@ -1,6 +1,4 @@
 # decoder ripped from: http://www.amnoid.de/gc/yaz0.txt
-# encoder ripped from:
-# https://bitbucket.org/ottehr/z64-fm/src/9fdc704ca42ff15c8e01b1566d4692d986920c6a/yaz0.c
 
 def decode(comp):
     src = 16 # skip header
@@ -51,6 +49,3 @@ def decode(comp):
         valid -= 1
 
     return uncomp
-
-def encode(uncomp):
-    raise Exception('Yaz0_encode: unimplemented')

Yaz0_fast.pyx

@@ -0,0 +1,58 @@
+# decoder ripped from: http://www.amnoid.de/gc/yaz0.txt
+
+ctypedef unsigned long ulong
+ctypedef unsigned char uchar
+
+cdef ulong get_size(uchar *comp):
+    return comp[4]*0x1000000 + comp[5]*0x10000 + comp[6]*0x100 + comp[7]
+
+cdef void _decode(uchar *comp, uchar *uncomp):
+    cdef:
+        ulong src = 16 # skip header
+        ulong dst = 0
+        uchar valid = 0 # bit count
+        uchar curr = 0 # code byte
+
+        ulong size = get_size(comp)
+
+        uchar byte1, byte2
+        ulong dist, copy, i, n
+
+    while dst < size:
+        if not valid:
+            curr = comp[src]
+            src += 1
+            valid = 8
+
+        if curr & 0x80:
+            uncomp[dst] = comp[src]
+            dst += 1
+            src += 1
+        else:
+            byte1 = comp[src]
+            byte2 = comp[src + 1]
+            src += 2
+
+            dist = ((byte1 & 0xF) << 8) | byte2
+            copy = dst - (dist + 1)
+
+            n = byte1 >> 4
+            if n:
+                n += 2
+            else:
+                n = comp[src] + 0x12
+                src += 1
+
+            for i in range(n):
+                uncomp[dst] = uncomp[copy]
+                copy += 1
+                dst += 1
+
+        curr <<= 1
+        valid -= 1
+
+def decode(comp):
+    size = get_size(comp)
+    uncomp = bytearray(size)
+    _decode(comp, uncomp)
+    return uncomp

n64.py

@@ -47,9 +47,7 @@ def crc(f, bootcode=6105):
 
         t3 ^= d
 
-        b = d & 0x1F
-        r = (d << b) | (d >> (32 - b))
-        r &= MAX32
+        r = ROL(d, d & 0x1F)
 
         t5 += r
         t5 &= MAX32

n64_fast.pyx

@@ -0,0 +1,87 @@
+# Based on uCON64's N64 checksum algorithm by Andreas Sterbenz
+
+ctypedef unsigned long ulong
+ctypedef unsigned char uchar
+
+# ulong must be 32 bits since we expect them to overflow as such
+# TODO: test on different machines
+assert(sizeof(ulong) == 4)
+
+from zlib import crc32
+
+crc_seeds = {
+    6101: 0xF8CA4DDC,
+    6102: 0xF8CA4DDC,
+    6103: 0xA3886759,
+    6105: 0xDF26F436,
+    6106: 0x1FEA617A,
+}
+
+bootcode_crcs = {
+    0x6170A4A1: 6101,
+    0x90BB6CB5: 6102,
+    0x0B050EE0: 6103,
+    0x98BC2C86: 6105,
+    0xACC8580A: 6106,
+}
+
+cdef ulong ROL(ulong i, ulong b):
+    return (i << b) | (i >> (32 - b))
+
+cdef ulong R4(uchar *b):
+    return b[0]*0x1000000 + b[1]*0x10000 + b[2]*0x100 + b[3]
+
+cdef object _crc(uchar *data, ulong bootcode, uchar *lookup):
+    cdef:
+        ulong seed = crc_seeds[bootcode]
+        ulong t1, t2, t3, t4, t5, t6
+        ulong i, d, b, r, o
+        ulong crc1, crc2
+
+    t1 = t2 = t3 = t4 = t5 = t6 = seed
+
+    for i in range(0x1000, 0x101000, 4):
+        d = R4(data + i)
+
+        if t6 + d < t6:
+            t4 += 1
+
+        t6 += d
+
+        t3 ^= d
+
+        r = ROL(d, d & 0x1F)
+
+        t5 += r
+
+        if t2 > d:
+            t2 ^= r
+        else:
+            t2 ^= t6 ^ d
+
+        if bootcode == 6105:
+            o = i & 0xFF
+            t1 += R4(lookup + o)^ d
+        else:
+            t1 += t5
+
+    if bootcode == 6103:
+        crc1 = (t6 ^ t4) + t3
+        crc2 = (t5 ^ t2) + t1
+    elif bootcode == 6106:
+        crc1 = t6*t4 + t3
+        crc2 = t5*t2 + t1
+    else:
+        crc1 = t6 ^ t4 ^ t3
+        crc2 = t5 ^ t2 ^ t1
+    return crc1, crc2
+
+def crc(f, bootcode=6105):
+    f.seek(0)
+    data = f.read()
+    lookup = data[0x750:0x850]
+    return _crc(data, bootcode, lookup)
+
+def bootcode_version(f):
+    f.seek(0x40)
+    return bootcode_crcs[crc32(f.read(0x1000 - 0x40)) & 0xFFFFFFFF]

z64dump.py

@@ -1,18 +1,32 @@
 #!/bin/python
-# shoutouts to spinout182
 
 import sys
 import os, os.path
 from io import BytesIO
 from hashlib import sha1
 
+# check for cython
+try:
+    import pyximport
+except ImportError:
+    fast = False
+else:
+    pyximport.install()
+    fast = True
+
+if fast:
+    import Yaz0_fast as Yaz0
+    import n64_fast as n64
+else:
+    import Yaz0
+    import n64
+
 from util import *
-from heuristics import *
-import n64
-import Yaz0
+from heuristics import detect_format
 
 lament = lambda *args, **kwargs: print(*args, file=sys.stderr, **kwargs)
 
+# shoutouts to spinout182
 # assume first entry is makerom (0x1060), and second entry begins from makerom
 dma_sig = b"\x00\x00\x00\x00\x00\x00\x10\x60\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x60"
 
@@ -22,7 +36,7 @@ def dump_wrap(data, fn, size):
         fn += '.' + kind
     dump_as(data, fn, size)
 
-def z_dump_file(f, i=0, name=None):
+def z_dump_file(f, i=0, name=None, uncompress=True):
     vs = R4(f.read(4)) # virtual start
     ve = R4(f.read(4)) # virtual end
     ps = R4(f.read(4)) # physical start
@@ -54,11 +68,18 @@ def z_dump_file(f, i=0, name=None):
         f.seek(ps)
         compressed = f.read(pe - ps)
         if compressed[:4] == b'Yaz0':
-            data = Yaz0.decode(compressed)
-            dump_wrap(data, fn, size)
+            if uncompress:
+                data = Yaz0.decode(compressed)
+                dump_wrap(data, fn, size)
+            else:
+                dump_wrap(compressed, fn+'.Yaz0', len(compressed))
         else:
-            lament('unknown compression; skipping:', fn)
-            lament(compressed[:4])
+            if uncompress:
+                lament('unknown compression; skipping:', fn)
+                lament(compressed[:4])
+            else:
+                lament('unknown compression:', fn)
+                dump_wrap(compressed, fn, len(compressed))
 
     f.seek(here)
     return True