MaxBufferSize() changed to MAX_BUFFER_SIZE. Also buffer will never grow more MAX_BUFFER_SIZE.

This commit is contained in:
Frank Stein
2015-08-07 21:19:02 +03:00
parent a1d801c375
commit 7bcbb19569

View File

@@ -87,13 +87,20 @@ class Builder(object):
__slots__ = ("Bytes", "current_vtable", "head", "minalign", "objectEnd", __slots__ = ("Bytes", "current_vtable", "head", "minalign", "objectEnd",
"vtables") "vtables")
"""
Maximum buffer size constant, in bytes.
Builder will never allow it's buffer grow over this size.
Currently equals 2Gb.
"""
MAX_BUFFER_SIZE = 2**31
def __init__(self, initialSize): def __init__(self, initialSize):
""" """
Initializes a Builder of size `initial_size`. Initializes a Builder of size `initial_size`.
The internal buffer is grown as needed. The internal buffer is grown as needed.
""" """
if not (0 <= initialSize <= self.MaxBufferSize()): if not (0 <= initialSize <= Builder.MAX_BUFFER_SIZE):
msg = "flatbuffers: Cannot create Builder larger than 2 gigabytes." msg = "flatbuffers: Cannot create Builder larger than 2 gigabytes."
raise BuilderSizeError(msg) raise BuilderSizeError(msg)
@@ -104,12 +111,6 @@ class Builder(object):
self.objectEnd = None self.objectEnd = None
self.vtables = [] self.vtables = []
def MaxBufferSize(self):
"""
Maximum buffer size is 2Gb.
"""
return 2**31
def Output(self): def Output(self):
""" """
Output returns the portion of the buffer that has been used for Output returns the portion of the buffer that has been used for
@@ -244,11 +245,11 @@ class Builder(object):
def growByteBuffer(self): def growByteBuffer(self):
"""Doubles the size of the byteslice, and copies the old data towards """Doubles the size of the byteslice, and copies the old data towards
the end of the new buffer (since we build the buffer backwards).""" the end of the new buffer (since we build the buffer backwards)."""
if not len(self.Bytes) <= self.MaxBufferSize(): if not len(self.Bytes) <= Builder.MAX_BUFFER_SIZE:
msg = "flatbuffers: cannot grow buffer beyond 2 gigabytes" msg = "flatbuffers: cannot grow buffer beyond 2 gigabytes"
raise BuilderSizeError(msg) raise BuilderSizeError(msg)
newSize = len(self.Bytes) * 2 newSize = min( len(self.Bytes) * 2, Builder.MAX_BUFFER_SIZE )
if newSize == 0: if newSize == 0:
newSize = 1 newSize = 1
bytes2 = bytearray(newSize) bytes2 = bytearray(newSize)