From e6be04c865885cf8fd7437587177612a4b8b2f8c Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Wed, 16 Oct 2013 01:23:10 +0900
Subject: [PATCH] Add auto-generation tools

---
 mkhufftbl.py     | 97 ++++++++++++++++++++++++++++++++++++++++++++++++
 mkstatichdtbl.py |  8 ++++
 2 files changed, 105 insertions(+)
 create mode 100755 mkhufftbl.py
 create mode 100755 mkstatichdtbl.py

diff --git a/mkhufftbl.py b/mkhufftbl.py
new file mode 100755
index 00000000..07611230
--- /dev/null
+++ b/mkhufftbl.py
@@ -0,0 +1,97 @@
+#!/usr/bin/env python
+import re
+import sys
+
+class Node:
+    def __init__(self, depth):
+        self.depth = depth
+        self.children = {}
+
+def to_bin(s):
+    res = []
+    for i in range(0, len(s), 8):
+        x = s[i:i+8]
+        x += '0'*(8 - len(x))
+        a = 0
+        for j in range(8):
+            a *= 2
+            a += ord(x[j]) - ord('0')
+        res.append(a) #chr(a))
+    return res
+
+nodes = []
+
+def insert(node, sym, binpat, nbits, pidx):
+    if pidx == len(binpat) - 1:
+        #assert(binpat[pidx] not in node.children)
+        mx = (8 - (nbits & 0x7)) & 0x7;
+        #print "last", bin(binpat[pidx]), mx
+        for i in range(1 << mx):
+            node.children[binpat[pidx] + i] = sym
+    else:
+        if binpat[pidx] not in node.children:
+            node.children[binpat[pidx]] = -len(nodes)
+            nextnode = Node(pidx + 1)
+            nodes.append(nextnode)
+        else:
+            nextnode = nodes[-node.children[binpat[pidx]]]
+        insert(nextnode, sym, binpat, nbits, pidx + 1)
+
+symbol_tbl = [(None, 0) for i in range(257)]
+tables = {}
+
+root = Node(0)
+nodes.append(root)
+
+for line in sys.stdin:
+    m = re.match(r'.*\(\s*(\d+)\) ([|01]+) \[(\d+)\] .*', line)
+    if m:
+        #print m.group(1), m.group(2), m.group(3)
+        sym = int(m.group(1))
+        pat = re.sub(r'\|', '', m.group(2))
+        nbits = int(m.group(3))
+        assert(len(pat) == nbits)
+        binpat = to_bin(pat)
+        assert(len(binpat) == (nbits+7)/8)
+        symbol_tbl[sym] = (binpat, nbits)
+        #print "Inserting", sym
+        insert(root, sym, binpat, nbits, 0)
+
+print '''\
+typedef struct {
+  size_t nbits;
+  uint8_t code[4];
+} nghttp2_huff_sym;
+'''
+
+print '''\
+nghttp2_huff_sym huff_sym_table[] = {'''
+for i in range(257):
+    pat = list(symbol_tbl[i][0])
+    pat += [0]*(4 - len(pat))
+    print '''\
+  {{ {}, {{ {} }} }}{}\
+'''.format(symbol_tbl[i][1], ', '.join([str(k) for k in pat]),
+           ',' if i < 256 else '')
+print '};'
+print ''
+
+print '''int16_t huff_decode_table[][256] = {'''
+for j in range(len(nodes)):
+    node = nodes[j]
+    print '/* {} */'.format(j)
+    print '{'
+    for i in range(256):
+        if i in node.children:
+            sys.stdout.write('''\
+ {}{}'''.format(node.children[i], ',' if i < 255 else ''))
+        else:
+            sys.stdout.write(''' NGHTTP2_HD_HUFF_NO_ENT,''')
+        if (i+1)&0x7 == 0:
+            print ''
+    sys.stdout.write('}')
+    if j == len(nodes) - 1:
+        print ''
+    else:
+        print ','
+print '};'
diff --git a/mkstatichdtbl.py b/mkstatichdtbl.py
new file mode 100755
index 00000000..495633d7
--- /dev/null
+++ b/mkstatichdtbl.py
@@ -0,0 +1,8 @@
+#!/usr/bin/env python
+import re, sys
+
+for line in sys.stdin:
+    m = re.match(r'(\d+)\s+(\S+)\s+(\S+)?', line)
+    print '/* {} */ "{}", "{}",'.format(m.group(1),
+                                        m.group(2),
+                                        m.group(3) if m.group(3) else '')