'21.07'21.07

1 files changed, 325 insertions, 0 deletions

diff --git a/C/XzIn.c b/C/XzIn.c
new file mode 100644
index 0000000..84f868e
--- /dev/null
+++ b/C/XzIn.c
@@ -0,0 +1,325 @@
+/* XzIn.c - Xz input
+2021-09-04 : Igor Pavlov : Public domain */
+
+#include "Precomp.h"
+
+#include <string.h>
+
+#include "7zCrc.h"
+#include "CpuArch.h"
+#include "Xz.h"
+
+/*
+#define XZ_FOOTER_SIG_CHECK(p) (memcmp((p), XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) == 0)
+*/
+#define XZ_FOOTER_SIG_CHECK(p) ((p)[0] == XZ_FOOTER_SIG_0 && (p)[1] == XZ_FOOTER_SIG_1)
+
+
+SRes Xz_ReadHeader(CXzStreamFlags *p, ISeqInStream *inStream)
+{
+  Byte sig[XZ_STREAM_HEADER_SIZE];
+  RINOK(SeqInStream_Read2(inStream, sig, XZ_STREAM_HEADER_SIZE, SZ_ERROR_NO_ARCHIVE));
+  if (memcmp(sig, XZ_SIG, XZ_SIG_SIZE) != 0)
+    return SZ_ERROR_NO_ARCHIVE;
+  return Xz_ParseHeader(p, sig);
+}
+
+#define READ_VARINT_AND_CHECK(buf, pos, size, res) \
+  { unsigned s = Xz_ReadVarInt(buf + pos, size - pos, res); \
+  if (s == 0) return SZ_ERROR_ARCHIVE; \
+  pos += s; }
+
+SRes XzBlock_ReadHeader(CXzBlock *p, ISeqInStream *inStream, BoolInt *isIndex, UInt32 *headerSizeRes)
+{
+  Byte header[XZ_BLOCK_HEADER_SIZE_MAX];
+  unsigned headerSize;
+  *headerSizeRes = 0;
+  RINOK(SeqInStream_ReadByte(inStream, &header[0]));
+  headerSize = (unsigned)header[0];
+  if (headerSize == 0)
+  {
+    *headerSizeRes = 1;
+    *isIndex = True;
+    return SZ_OK;
+  }
+
+  *isIndex = False;
+  headerSize = (headerSize << 2) + 4;
+  *headerSizeRes = headerSize;
+  RINOK(SeqInStream_Read(inStream, header + 1, headerSize - 1));
+  return XzBlock_Parse(p, header);
+}
+
+#define ADD_SIZE_CHECK(size, val) \
+  { UInt64 newSize = size + (val); if (newSize < size) return XZ_SIZE_OVERFLOW; size = newSize; }
+
+UInt64 Xz_GetUnpackSize(const CXzStream *p)
+{
+  UInt64 size = 0;
+  size_t i;
+  for (i = 0; i < p->numBlocks; i++)
+    ADD_SIZE_CHECK(size, p->blocks[i].unpackSize);
+  return size;
+}
+
+UInt64 Xz_GetPackSize(const CXzStream *p)
+{
+  UInt64 size = 0;
+  size_t i;
+  for (i = 0; i < p->numBlocks; i++)
+    ADD_SIZE_CHECK(size, (p->blocks[i].totalSize + 3) & ~(UInt64)3);
+  return size;
+}
+
+/*
+SRes XzBlock_ReadFooter(CXzBlock *p, CXzStreamFlags f, ISeqInStream *inStream)
+{
+  return SeqInStream_Read(inStream, p->check, XzFlags_GetCheckSize(f));
+}
+*/
+
+static SRes Xz_ReadIndex2(CXzStream *p, const Byte *buf, size_t size, ISzAllocPtr alloc)
+{
+  size_t numBlocks, pos = 1;
+  UInt32 crc;
+
+  if (size < 5 || buf[0] != 0)
+    return SZ_ERROR_ARCHIVE;
+
+  size -= 4;
+  crc = CrcCalc(buf, size);
+  if (crc != GetUi32(buf + size))
+    return SZ_ERROR_ARCHIVE;
+
+  {
+    UInt64 numBlocks64;
+    READ_VARINT_AND_CHECK(buf, pos, size, &numBlocks64);
+    numBlocks = (size_t)numBlocks64;
+    if (numBlocks != numBlocks64 || numBlocks * 2 > size)
+      return SZ_ERROR_ARCHIVE;
+  }
+  
+  Xz_Free(p, alloc);
+  if (numBlocks != 0)
+  {
+    size_t i;
+    p->numBlocks = numBlocks;
+    p->blocks = (CXzBlockSizes *)ISzAlloc_Alloc(alloc, sizeof(CXzBlockSizes) * numBlocks);
+    if (!p->blocks)
+      return SZ_ERROR_MEM;
+    for (i = 0; i < numBlocks; i++)
+    {
+      CXzBlockSizes *block = &p->blocks[i];
+      READ_VARINT_AND_CHECK(buf, pos, size, &block->totalSize);
+      READ_VARINT_AND_CHECK(buf, pos, size, &block->unpackSize);
+      if (block->totalSize == 0)
+        return SZ_ERROR_ARCHIVE;
+    }
+  }
+  while ((pos & 3) != 0)
+    if (buf[pos++] != 0)
+      return SZ_ERROR_ARCHIVE;
+  return (pos == size) ? SZ_OK : SZ_ERROR_ARCHIVE;
+}
+
+static SRes Xz_ReadIndex(CXzStream *p, ILookInStream *stream, UInt64 indexSize, ISzAllocPtr alloc)
+{
+  SRes res;
+  size_t size;
+  Byte *buf;
+  if (indexSize > ((UInt32)1 << 31))
+    return SZ_ERROR_UNSUPPORTED;
+  size = (size_t)indexSize;
+  if (size != indexSize)
+    return SZ_ERROR_UNSUPPORTED;
+  buf = (Byte *)ISzAlloc_Alloc(alloc, size);
+  if (!buf)
+    return SZ_ERROR_MEM;
+  res = LookInStream_Read2(stream, buf, size, SZ_ERROR_UNSUPPORTED);
+  if (res == SZ_OK)
+    res = Xz_ReadIndex2(p, buf, size, alloc);
+  ISzAlloc_Free(alloc, buf);
+  return res;
+}
+
+static SRes LookInStream_SeekRead_ForArc(ILookInStream *stream, UInt64 offset, void *buf, size_t size)
+{
+  RINOK(LookInStream_SeekTo(stream, offset));
+  return LookInStream_Read(stream, buf, size);
+  /* return LookInStream_Read2(stream, buf, size, SZ_ERROR_NO_ARCHIVE); */
+}
+
+static SRes Xz_ReadBackward(CXzStream *p, ILookInStream *stream, Int64 *startOffset, ISzAllocPtr alloc)
+{
+  UInt64 indexSize;
+  Byte buf[XZ_STREAM_FOOTER_SIZE];
+  UInt64 pos = (UInt64)*startOffset;
+
+  if ((pos & 3) != 0 || pos < XZ_STREAM_FOOTER_SIZE)
+    return SZ_ERROR_NO_ARCHIVE;
+
+  pos -= XZ_STREAM_FOOTER_SIZE;
+  RINOK(LookInStream_SeekRead_ForArc(stream, pos, buf, XZ_STREAM_FOOTER_SIZE));
+  
+  if (!XZ_FOOTER_SIG_CHECK(buf + 10))
+  {
+    UInt32 total = 0;
+    pos += XZ_STREAM_FOOTER_SIZE;
+    
+    for (;;)
+    {
+      size_t i;
+      #define TEMP_BUF_SIZE (1 << 10)
+      Byte temp[TEMP_BUF_SIZE];
+      
+      i = (pos > TEMP_BUF_SIZE) ? TEMP_BUF_SIZE : (size_t)pos;
+      pos -= i;
+      RINOK(LookInStream_SeekRead_ForArc(stream, pos, temp, i));
+      total += (UInt32)i;
+      for (; i != 0; i--)
+        if (temp[i - 1] != 0)
+          break;
+      if (i != 0)
+      {
+        if ((i & 3) != 0)
+          return SZ_ERROR_NO_ARCHIVE;
+        pos += i;
+        break;
+      }
+      if (pos < XZ_STREAM_FOOTER_SIZE || total > (1 << 16))
+        return SZ_ERROR_NO_ARCHIVE;
+    }
+    
+    if (pos < XZ_STREAM_FOOTER_SIZE)
+      return SZ_ERROR_NO_ARCHIVE;
+    pos -= XZ_STREAM_FOOTER_SIZE;
+    RINOK(LookInStream_SeekRead_ForArc(stream, pos, buf, XZ_STREAM_FOOTER_SIZE));
+    if (!XZ_FOOTER_SIG_CHECK(buf + 10))
+      return SZ_ERROR_NO_ARCHIVE;
+  }
+  
+  p->flags = (CXzStreamFlags)GetBe16(buf + 8);
+
+  if (!XzFlags_IsSupported(p->flags))
+    return SZ_ERROR_UNSUPPORTED;
+
+  {
+    /* to eliminate GCC 6.3 warning:
+       dereferencing type-punned pointer will break strict-aliasing rules */
+    const Byte *buf_ptr = buf;
+    if (GetUi32(buf_ptr) != CrcCalc(buf + 4, 6))
+      return SZ_ERROR_ARCHIVE;
+  }
+
+  indexSize = ((UInt64)GetUi32(buf + 4) + 1) << 2;
+
+  if (pos < indexSize)
+    return SZ_ERROR_ARCHIVE;
+
+  pos -= indexSize;
+  RINOK(LookInStream_SeekTo(stream, pos));
+  RINOK(Xz_ReadIndex(p, stream, indexSize, alloc));
+
+  {
+    UInt64 totalSize = Xz_GetPackSize(p);
+    if (totalSize == XZ_SIZE_OVERFLOW
+        || totalSize >= ((UInt64)1 << 63)
+        || pos < totalSize + XZ_STREAM_HEADER_SIZE)
+      return SZ_ERROR_ARCHIVE;
+    pos -= (totalSize + XZ_STREAM_HEADER_SIZE);
+    RINOK(LookInStream_SeekTo(stream, pos));
+    *startOffset = (Int64)pos;
+  }
+  {
+    CXzStreamFlags headerFlags;
+    CSecToRead secToRead;
+    SecToRead_CreateVTable(&secToRead);
+    secToRead.realStream = stream;
+
+    RINOK(Xz_ReadHeader(&headerFlags, &secToRead.vt));
+    return (p->flags == headerFlags) ? SZ_OK : SZ_ERROR_ARCHIVE;
+  }
+}
+
+
+/* ---------- Xz Streams ---------- */
+
+void Xzs_Construct(CXzs *p)
+{
+  p->num = p->numAllocated = 0;
+  p->streams = 0;
+}
+
+void Xzs_Free(CXzs *p, ISzAllocPtr alloc)
+{
+  size_t i;
+  for (i = 0; i < p->num; i++)
+    Xz_Free(&p->streams[i], alloc);
+  ISzAlloc_Free(alloc, p->streams);
+  p->num = p->numAllocated = 0;
+  p->streams = 0;
+}
+
+UInt64 Xzs_GetNumBlocks(const CXzs *p)
+{
+  UInt64 num = 0;
+  size_t i;
+  for (i = 0; i < p->num; i++)
+    num += p->streams[i].numBlocks;
+  return num;
+}
+
+UInt64 Xzs_GetUnpackSize(const CXzs *p)
+{
+  UInt64 size = 0;
+  size_t i;
+  for (i = 0; i < p->num; i++)
+    ADD_SIZE_CHECK(size, Xz_GetUnpackSize(&p->streams[i]));
+  return size;
+}
+
+/*
+UInt64 Xzs_GetPackSize(const CXzs *p)
+{
+  UInt64 size = 0;
+  size_t i;
+  for (i = 0; i < p->num; i++)
+    ADD_SIZE_CHECK(size, Xz_GetTotalSize(&p->streams[i]));
+  return size;
+}
+*/
+
+SRes Xzs_ReadBackward(CXzs *p, ILookInStream *stream, Int64 *startOffset, ICompressProgress *progress, ISzAllocPtr alloc)
+{
+  Int64 endOffset = 0;
+  RINOK(ILookInStream_Seek(stream, &endOffset, SZ_SEEK_END));
+  *startOffset = endOffset;
+  for (;;)
+  {
+    CXzStream st;
+    SRes res;
+    Xz_Construct(&st);
+    res = Xz_ReadBackward(&st, stream, startOffset, alloc);
+    st.startOffset = (UInt64)*startOffset;
+    RINOK(res);
+    if (p->num == p->numAllocated)
+    {
+      const size_t newNum = p->num + p->num / 4 + 1;
+      void *data = ISzAlloc_Alloc(alloc, newNum * sizeof(CXzStream));
+      if (!data)
+        return SZ_ERROR_MEM;
+      p->numAllocated = newNum;
+      if (p->num != 0)
+        memcpy(data, p->streams, p->num * sizeof(CXzStream));
+      ISzAlloc_Free(alloc, p->streams);
+      p->streams = (CXzStream *)data;
+    }
+    p->streams[p->num++] = st;
+    if (*startOffset == 0)
+      break;
+    RINOK(LookInStream_SeekTo(stream, (UInt64)*startOffset));
+    if (progress && ICompressProgress_Progress(progress, (UInt64)(endOffset - *startOffset), (UInt64)(Int64)-1) != SZ_OK)
+      return SZ_ERROR_PROGRESS;
+  }
+  return SZ_OK;
+}