intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 65 insertions, 0 deletions

diff --git a/util/stream/mem.cpp b/util/stream/mem.cpp
new file mode 100644
index 00000000000..22a3339e274
--- /dev/null
+++ b/util/stream/mem.cpp
@@ -0,0 +1,65 @@
+#include "mem.h"
+
+#include <util/generic/yexception.h>
+
+TMemoryInput::TMemoryInput() noexcept
+    : Buf_(nullptr)
+    , Len_(0)
+{
+}
+
+TMemoryInput::TMemoryInput(const void* buf, size_t len) noexcept
+    : Buf_((const char*)buf)
+    , Len_(len)
+{
+}
+
+TMemoryInput::TMemoryInput(const TStringBuf buf) noexcept
+    : Buf_(buf.data())
+    , Len_(buf.size())
+{
+}
+
+TMemoryInput::~TMemoryInput() = default;
+
+size_t TMemoryInput::DoNext(const void** ptr, size_t len) {
+    len = Min(Len_, len);
+
+    *ptr = Buf_;
+    Len_ -= len;
+    Buf_ += len;
+    return len;
+}
+
+void TMemoryInput::DoUndo(size_t len) {
+    Len_ += len;
+    Buf_ -= len;
+}
+
+TMemoryOutput::~TMemoryOutput() = default;
+
+size_t TMemoryOutput::DoNext(void** ptr) {
+    Y_ENSURE(Buf_ < End_, TStringBuf("memory output stream exhausted"));
+    *ptr = Buf_;
+    size_t bufferSize = End_ - Buf_;
+    Buf_ = End_;
+
+    return bufferSize;
+}
+
+void TMemoryOutput::DoUndo(size_t len) {
+    Buf_ -= len;
+}
+
+void TMemoryOutput::DoWrite(const void* buf, size_t len) {
+    char* end = Buf_ + len;
+    Y_ENSURE(end <= End_, TStringBuf("memory output stream exhausted"));
+
+    memcpy(Buf_, buf, len);
+    Buf_ = end;
+}
+
+void TMemoryOutput::DoWriteC(char c) {
+    Y_ENSURE(Buf_ < End_, TStringBuf("memory output stream exhausted"));
+    *Buf_++ = c;
+}