From f1f89d3f0f7192c06a73118e84adf50b1954f857 Mon Sep 17 00:00:00 2001
From: Stenzek <stenzek@gmail.com>
Date: Sun, 21 Jul 2024 13:33:41 +1000
Subject: [PATCH] BinarySpanReaderWriter: Add subspan methods

---
 src/common/binary_span_reader_writer.cpp | 35 ++++++++++++++++++++++++
 src/common/binary_span_reader_writer.h   |  8 ++++++
 2 files changed, 43 insertions(+)

diff --git a/src/common/binary_span_reader_writer.cpp b/src/common/binary_span_reader_writer.cpp
index e1011da00..a0ac8078b 100644
--- a/src/common/binary_span_reader_writer.cpp
+++ b/src/common/binary_span_reader_writer.cpp
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
 
 #include "binary_span_reader_writer.h"
+#include "assert.h"
 #include "small_string.h"
 
 BinarySpanReader::BinarySpanReader() = default;
@@ -30,6 +31,23 @@ bool BinarySpanReader::PeekCString(std::string_view* dst)
   return true;
 }
 
+std::span<const u8> BinarySpanReader::GetRemainingSpan(size_t size) const
+{
+  DebugAssert(size <= GetBufferRemaining());
+  return m_buf.subspan(m_pos, size);
+}
+
+std::span<const u8> BinarySpanReader::GetRemainingSpan() const
+{
+  return m_buf.subspan(m_pos, m_buf.size() - m_pos);
+}
+
+void BinarySpanReader::IncrementPosition(size_t size)
+{
+  DebugAssert(size < GetBufferRemaining());
+  m_pos += size;
+}
+
 bool BinarySpanReader::ReadCString(std::string* dst)
 {
   std::string_view sv;
@@ -96,6 +114,23 @@ BinarySpanWriter::BinarySpanWriter(std::span<u8> buf) : m_buf(buf)
 {
 }
 
+std::span<u8> BinarySpanWriter::GetRemainingSpan(size_t size) const
+{
+  DebugAssert(size <= GetBufferRemaining());
+  return m_buf.subspan(m_pos, size);
+}
+
+std::span<u8> BinarySpanWriter::GetRemainingSpan() const
+{
+  return m_buf.subspan(m_pos, m_buf.size() - m_pos);
+}
+
+void BinarySpanWriter::IncrementPosition(size_t size)
+{
+  DebugAssert(size < GetBufferRemaining());
+  m_pos += size;
+}
+
 bool BinarySpanWriter::WriteCString(std::string_view val)
 {
   if ((m_pos + val.size() + 1) > m_buf.size()) [[unlikely]]
diff --git a/src/common/binary_span_reader_writer.h b/src/common/binary_span_reader_writer.h
index 7bae91a4a..643047a39 100644
--- a/src/common/binary_span_reader_writer.h
+++ b/src/common/binary_span_reader_writer.h
@@ -22,6 +22,10 @@ public:
   ALWAYS_INLINE size_t GetBufferRemaining() const { return (m_buf.size() - m_pos); }
   ALWAYS_INLINE size_t GetBufferConsumed() const { return m_pos; }
 
+  std::span<const u8> GetRemainingSpan() const;
+  std::span<const u8> GetRemainingSpan(size_t size) const;
+  void IncrementPosition(size_t size);
+
   // clang-format off
   template<typename T> ALWAYS_INLINE bool ReadT(T* dst) { return Read(dst, sizeof(T)); }
   ALWAYS_INLINE bool ReadU8(u8* dst) { return ReadT(dst); }
@@ -99,6 +103,10 @@ public:
   ALWAYS_INLINE size_t GetBufferRemaining() const { return (m_buf.size() - m_pos); }
   ALWAYS_INLINE size_t GetBufferWritten() const { return m_pos; }
 
+  std::span<u8> GetRemainingSpan() const;
+  std::span<u8> GetRemainingSpan(size_t size) const;
+  void IncrementPosition(size_t size);
+
   // clang-format off
   template<typename T> ALWAYS_INLINE bool WriteT(T dst) { return Write(&dst, sizeof(T)); }
   ALWAYS_INLINE bool WriteU8(u8 val) { return WriteT(val); }