Squashed 'python/fsb5/' content from commit 5acfaed

git-subtree-dir: python/fsb5
git-subtree-split: 5acfaed9b44167eeebbd5f0414745cc23a2104a7

fsb5/utils.py

@@ -0,0 +1,76 @@
+import os
+import ctypes
+import struct
+
+
+class BinaryReader:
+	def __init__(self, buf, endian="<"):
+		self.buf = buf
+		self.endian = endian
+		self.seek(0, 2)
+		self.size = self.tell()
+		self.seek(0)
+
+	def read(self, *args):
+		return self.buf.read(*args)
+
+	def seek(self, *args):
+		return self.buf.seek(*args)
+
+	def tell(self):
+		return self.buf.tell()
+
+	def finished(self):
+		return self.tell() == self.size
+
+	def read_string(self, maxlen=0):
+		r = []
+		start = self.tell()
+		while maxlen == 0 or len(r) <= maxlen:
+			c = self.read(1)
+			if not c:
+				raise ValueError("Unterminated string starting at %d" % (start))
+			if c == b"\0":
+				break
+			r.append(c)
+		return b"".join(r)
+
+	def struct_calcsize(self, fmt):
+		return struct.calcsize(fmt)
+
+	def read_struct(self, fmt, endian=None):
+		fmt = (endian or self.endian) + fmt;
+		fmtlen = struct.calcsize(fmt)
+		data = self.read(fmtlen)
+		if len(data) != fmtlen:
+			raise ValueError("Not enough bytes left in buffer to read struct")
+		return struct.unpack(fmt, data)
+
+	def read_struct_into(self, dest, fmt, endian=None):
+		fields = self.read_struct(fmt, endian=endian)
+		fields = list(fields) + [None] * (len(dest._fields) - len(fields))
+		return dest._make(fields)
+
+	def read_type(self, type_fmt, endian=None):
+		r = self.read_struct(type_fmt, endian=endian)
+		if len(r) != 1:
+			raise ValueError("Format %r did not describe a single type" % (type_fmt))
+		return r[0]
+
+
+class LibraryNotFoundException(OSError):
+    pass
+
+
+def load_lib(*names):
+	for name in names:
+		try:
+			libname = ctypes.util.find_library(name)
+			if libname:
+				return ctypes.CDLL(libname)
+			else:
+				dll_path = os.path.join(os.getcwd(), "lib%s.dll" % (name))
+				return ctypes.CDLL(dll_path)
+		except OSError:
+			pass
+	raise LibraryNotFoundException("Could not load the library %r" % (names[0]))