intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 56 insertions, 0 deletions

diff --git a/library/cpp/yt/coding/varint.h b/library/cpp/yt/coding/varint.h
new file mode 100644
index 0000000000..c5399f8b06
--- /dev/null
+++ b/library/cpp/yt/coding/varint.h
@@ -0,0 +1,56 @@
+#pragma once
+
+#include <library/cpp/yt/exception/exception.h>
+
+#include <util/system/defaults.h>
+
+#include <util/stream/input.h>
+#include <util/stream/output.h>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+constexpr size_t MaxVarInt64Size = (8 * sizeof(ui64) - 1) / 7 + 1;
+constexpr size_t MaxVarUint64Size = (8 * sizeof(ui64) - 1) / 7 + 1;
+
+constexpr size_t MaxVarInt32Size = (8 * sizeof(ui32) - 1) / 7 + 1;
+constexpr size_t MaxVarUint32Size = (8 * sizeof(ui32) - 1) / 7 + 1;
+
+// Various functions to read/write varints.
+
+// Returns the number of bytes written.
+int WriteVarUint64(IOutputStream* output, ui64 value);
+int WriteVarUint32(IOutputStream* output, ui32 value);
+int WriteVarInt32(IOutputStream* output, i32 value);
+int WriteVarInt64(IOutputStream* output, i64 value);
+
+int WriteVarUint64(char* output, ui64 value);
+int WriteVarUint32(char* output, ui32 value);
+int WriteVarInt32(char* output, i32 value);
+int WriteVarInt64(char* output, i64 value);
+
+// Returns the number of bytes read.
+int ReadVarUint64(IInputStream* input, ui64* value);
+int ReadVarUint32(IInputStream* input, ui32* value);
+int ReadVarInt32(IInputStream* input, i32* value);
+int ReadVarInt64(IInputStream* input, i64* value);
+
+int ReadVarUint64(const char* input, ui64* value);
+int ReadVarUint32(const char* input, ui32* value);
+int ReadVarInt32(const char* input, i32* value);
+int ReadVarInt64(const char* input, i64* value);
+
+// Throws exception if integer is not complete when `end' is reached.
+int ReadVarUint64(const char* input, const char* end, ui64* value);
+int ReadVarUint32(const char* input, const char* end, ui32* value);
+int ReadVarInt32(const char* input, const char* end, i32* value);
+int ReadVarInt64(const char* input, const char* end, i64* value);
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
+
+#define VARINT_INL_H_
+#include "varint-inl.h"
+#undef VARINT_INL_H_