update

1 files changed, 47 insertions, 0 deletions

diff --git a/misc.py b/misc.py
new file mode 100755
index 0000000..b7120e2
--- /dev/null
+++ b/misc.py
@@ -0,0 +1,47 @@
+
+def LEB128UnsignedDecode(bytelist):
+    result = 0
+    shift = 0
+    for byte in bytelist:
+        result |= (byte & 0x7f) << shift
+        if (byte & 0x80) == 0:
+            break
+        shift += 7
+    return(result)
+
+def LEB128SignedDecode(bytelist):
+    result = 0
+    shift = 0
+    for byte in bytelist:
+        result |= (byte & 0x7f) << shift
+        last_byte = byte
+        shift += 7
+        if (byte & 0x80) == 0:
+            break
+    if last_byte & 0x40:
+        result |= - (1 << shift)
+    return(result)
+
+def LEB128UnsignedEncode(int_val):
+    if int_val < 0:
+        raise Exception("value must not be negative")
+    elif int_val == 0:
+        return bytes([0])
+    byte_array = bytearray()
+    while int_val:
+        byte = int_val & 0x7f
+        byte_array.append(byte | 0x80)
+        int_val >>= 7
+    byte_array[-1] ^= 0x80
+    return(byte_array)
+
+def LEB128SignedEncode(int_val):
+    byte_array = bytearray()
+    while True:
+        byte = int_val & 0x7f
+        byte_array.append(byte | 0x80)
+        int_val >>= 7
+        if (int_val == 0 and byte&0x40 == 0) or (int_val == -1 and byte&0x40):
+            byte_array[-1] ^= 0x80
+            break
+    return(byte_array)