chore: initial commit (extracted from Launchers monorepo)

Plugin: ns7zip v2.0.0 Architectures: x86-ansi, x86-unicode, amd64-unicode License: LGPL-2.1-or-later
2026-04-29 14:07:51 +02:00
commit d074cc7c07
3848 changed files with 1076682 additions and 0 deletions
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+// FindSignature.cpp
+
+#include "StdAfx.h"
+
+#include <string.h>
+
+#include "../../../Common/MyBuffer.h"
+
+#include "../../Common/StreamUtils.h"
+
+#include "FindSignature.h"
+
+HRESULT FindSignatureInStream(ISequentialInStream *stream,
+    const Byte *signature, unsigned signatureSize,
+    const UInt64 *limit, UInt64 &resPos)
+{
+  resPos = 0;
+  CByteBuffer byteBuffer2(signatureSize);
+  RINOK(ReadStream_FALSE(stream, byteBuffer2, signatureSize))
+
+  if (memcmp(byteBuffer2, signature, signatureSize) == 0)
+    return S_OK;
+
+  const size_t kBufferSize = 1 << 16;
+  CByteBuffer byteBuffer(kBufferSize);
+  Byte *buffer = byteBuffer;
+  size_t numPrevBytes = signatureSize - 1;
+  memcpy(buffer, (const Byte *)byteBuffer2 + 1, numPrevBytes);
+  resPos = 1;
+  for (;;)
+  {
+    if (limit)
+      if (resPos > *limit)
+        return S_FALSE;
+    do
+    {
+      const size_t numReadBytes = kBufferSize - numPrevBytes;
+      UInt32 processedSize;
+      RINOK(stream->Read(buffer + numPrevBytes, (UInt32)numReadBytes, &processedSize))
+      numPrevBytes += (size_t)processedSize;
+      if (processedSize == 0)
+        return S_FALSE;
+    }
+    while (numPrevBytes < signatureSize);
+    const size_t numTests = numPrevBytes - signatureSize + 1;
+    for (size_t pos = 0; pos < numTests; pos++)
+    {
+      const Byte b = signature[0];
+      for (; buffer[pos] != b && pos < numTests; pos++);
+      if (pos == numTests)
+        break;
+      if (memcmp(buffer + pos, signature, signatureSize) == 0)
+      {
+        resPos += pos;
+        return S_OK;
+      }
+    }
+    resPos += numTests;
+    numPrevBytes -= numTests;
+    memmove(buffer, buffer + numTests, numPrevBytes);
+  }
+}
+
+namespace NArchive {
+HRESULT ReadZeroTail(ISequentialInStream *stream, bool &areThereNonZeros, UInt64 &numZeros, UInt64 maxSize);
+HRESULT ReadZeroTail(ISequentialInStream *stream, bool &areThereNonZeros, UInt64 &numZeros, UInt64 maxSize)
+{
+  areThereNonZeros = false;
+  numZeros = 0;
+  const size_t kBufSize = 1 << 11;
+  Byte buf[kBufSize];
+  for (;;)
+  {
+    UInt32 size = 0;
+    RINOK(stream->Read(buf, kBufSize, &size))
+    if (size == 0)
+      return S_OK;
+    for (UInt32 i = 0; i < size; i++)
+      if (buf[i] != 0)
+      {
+        areThereNonZeros = true;
+        numZeros += i;
+        return S_OK;
+      }
+    numZeros += size;
+    if (numZeros > maxSize)
+      return S_OK;
+  }
+}
+}