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authorSamuel Barney <samjbarney@gmail.com>2013-10-28 23:40:13 +0100
committerSamuel Barney <samjbarney@gmail.com>2013-10-28 23:40:13 +0100
commitd7a490a99205d69abce52c77854fafee52b4e82b (patch)
tree92e68ff622fc89bd94e11c7ed7fc548ed3129047 /source/ByteBuffer.cpp
parentGot spiders and other mobs respecting night and day for spawning (diff)
parentProtoProxy: Implemented 1.7.2 status request / response / ping. (diff)
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Diffstat (limited to 'source/ByteBuffer.cpp')
-rw-r--r--source/ByteBuffer.cpp130
1 files changed, 128 insertions, 2 deletions
diff --git a/source/ByteBuffer.cpp b/source/ByteBuffer.cpp
index c82951271..6659b4dd4 100644
--- a/source/ByteBuffer.cpp
+++ b/source/ByteBuffer.cpp
@@ -13,8 +13,54 @@
-#define NEEDBYTES(Num) if (!CanReadBytes(Num)) return false;
-#define PUTBYTES(Num) if (!CanWriteBytes(Num)) return false;
+// If a string sent over the protocol is larger than this, a warning is emitted to the console
+#define MAX_STRING_SIZE (512 KiB)
+
+#define NEEDBYTES(Num) if (!CanReadBytes(Num)) return false; // Check if at least Num bytes can be read from the buffer, return false if not
+#define PUTBYTES(Num) if (!CanWriteBytes(Num)) return false; // Check if at least Num bytes can be written to the buffer, return false if not
+
+
+
+
+
+#if 0
+
+/// Self-test of the VarInt-reading and writing code
+class cByteBufferSelfTest
+{
+public:
+ cByteBufferSelfTest(void)
+ {
+ TestRead();
+ TestWrite();
+ }
+
+ void TestRead(void)
+ {
+ cByteBuffer buf(50);
+ buf.Write("\x05\xac\x02\x00", 4);
+ UInt32 v1;
+ ASSERT(buf.ReadVarInt(v1) && (v1 == 5));
+ UInt32 v2;
+ ASSERT(buf.ReadVarInt(v2) && (v2 == 300));
+ UInt32 v3;
+ ASSERT(buf.ReadVarInt(v3) && (v3 == 0));
+ }
+
+ void TestWrite(void)
+ {
+ cByteBuffer buf(50);
+ buf.WriteVarInt(5);
+ buf.WriteVarInt(300);
+ buf.WriteVarInt(0);
+ AString All;
+ buf.ReadAll(All);
+ ASSERT(All.size() == 4);
+ ASSERT(memcmp(All.data(), "\x05\xac\x02\x00", All.size()) == 0);
+ }
+} g_ByteBufferTest;
+
+#endif
@@ -328,6 +374,48 @@ bool cByteBuffer::ReadBEUTF16String16(AString & a_Value)
+bool cByteBuffer::ReadVarInt(UInt32 & a_Value)
+{
+ CHECK_THREAD;
+ CheckValid();
+ UInt32 Value = 0;
+ int Shift = 0;
+ unsigned char b = 0;
+ do
+ {
+ NEEDBYTES(1);
+ ReadBuf(&b, 1);
+ Value = Value | (((Int64)(b & 0x7f)) << Shift);
+ Shift += 7;
+ } while ((b & 0x80) != 0);
+ a_Value = Value;
+ return true;
+}
+
+
+
+
+
+bool cByteBuffer::ReadVarUTF8String(AString & a_Value)
+{
+ CHECK_THREAD;
+ CheckValid();
+ UInt32 Size = 0;
+ if (!ReadVarInt(Size))
+ {
+ return false;
+ }
+ if (Size > MAX_STRING_SIZE)
+ {
+ LOGWARNING("%s: String too large: %llu (%llu KiB)", __FUNCTION__, Size, Size / 1024);
+ }
+ return ReadString(a_Value, (int)Size);
+}
+
+
+
+
+
bool cByteBuffer::WriteChar(char a_Value)
{
CHECK_THREAD;
@@ -446,6 +534,44 @@ bool cByteBuffer::WriteBEUTF16String16(const AString & a_Value)
+bool cByteBuffer::WriteVarInt(UInt32 a_Value)
+{
+ CHECK_THREAD;
+ CheckValid();
+
+ // A 32-bit integer can be encoded by at most 5 bytes:
+ unsigned char b[5];
+ int idx = 0;
+ do
+ {
+ b[idx] = (a_Value & 0x7f) | ((a_Value > 0x7f) ? 0x80 : 0x00);
+ a_Value = a_Value >> 7;
+ idx++;
+ } while (a_Value > 0);
+
+ return WriteBuf(b, idx);
+}
+
+
+
+
+bool cByteBuffer::WriteVarUTF8String(AString & a_Value)
+{
+ CHECK_THREAD;
+ CheckValid();
+ PUTBYTES(a_Value.size() + 1); // This is a lower-bound on the bytes that will be actually written. Fail early.
+ bool res = WriteVarInt(a_Value.size());
+ if (!res)
+ {
+ return false;
+ }
+ return WriteBuf(a_Value.data(), a_Value.size());
+}
+
+
+
+
+
bool cByteBuffer::ReadBuf(void * a_Buffer, int a_Count)
{
CHECK_THREAD;