Common: Add MinizipHelpers (RAM and UTF-8 compatible fopen)

src/common/minizip_helpers.cpp

@@ -0,0 +1,90 @@
+#include "minizip_helpers.h"
+#include "file_system.h"
+#include "ioapi.h"
+#include "types.h"
+#include <algorithm>
+
+namespace MinizipHelpers {
+
+unzFile OpenUnzMemoryFile(const void* memory, size_t memory_size)
+{
+  struct MemoryFileInfo
+  {
+    const u8* data;
+    ZPOS64_T data_size;
+    ZPOS64_T position;
+  };
+
+  MemoryFileInfo* fi = new MemoryFileInfo;
+  fi->data = static_cast<const u8*>(memory);
+  fi->data_size = static_cast<ZPOS64_T>(memory_size);
+  fi->position = 0;
+
+#define FI static_cast<MemoryFileInfo*>(stream)
+
+  zlib_filefunc64_def funcs = {
+    [](voidpf opaque, const void* filename, int mode) -> voidpf { return opaque; }, // open
+    [](voidpf opaque, voidpf stream, void* buf, uLong size) -> uLong {              // read
+      const ZPOS64_T remaining = FI->data_size - FI->position;
+      const ZPOS64_T to_read = std::min(remaining, static_cast<ZPOS64_T>(size));
+      if (to_read > 0)
+      {
+        std::memcpy(buf, FI->data + FI->position, to_read);
+        FI->position += to_read;
+      }
+
+      return static_cast<uLong>(to_read);
+    },
+    [](voidpf opaque, voidpf stream, const void* buf, uLong size) -> uLong { return 0; },         // write
+    [](voidpf opaque, voidpf stream) -> ZPOS64_T { return static_cast<ZPOS64_T>(FI->position); }, // tell
+    [](voidpf opaque, voidpf stream, ZPOS64_T offset, int origin) -> long {                       // seek
+      ZPOS64_T new_position = FI->position;
+      if (origin == SEEK_SET)
+        new_position = static_cast<int>(offset);
+      else if (origin == SEEK_CUR)
+        new_position += static_cast<int>(offset);
+      else
+        new_position = FI->data_size;
+      if (new_position < 0 || new_position > FI->data_size)
+        return -1;
+
+      FI->position = new_position;
+      return 0;
+    },
+    [](voidpf opaque, voidpf stream) -> int {
+      delete FI;
+      return 0;
+    },                                                     // close
+    [](voidpf opaque, voidpf stream) -> int { return 0; }, // testerror
+    static_cast<voidpf>(fi)};
+
+#undef FI
+
+  unzFile zf = unzOpen2_64("", &funcs);
+  if (!zf)
+    delete fi;
+
+  return zf;
+}
+
+unzFile OpenUnzFile(const char* filename)
+{
+  zlib_filefunc64_def funcs;
+  fill_fopen64_filefunc(&funcs);
+
+  funcs.zopen64_file = [](voidpf opaque, const void* filename, int mode) -> voidpf {
+    const char* mode_fopen = NULL;
+    if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER) == ZLIB_FILEFUNC_MODE_READ)
+      mode_fopen = "rb";
+    else if (mode & ZLIB_FILEFUNC_MODE_EXISTING)
+      mode_fopen = "r+b";
+    else if (mode & ZLIB_FILEFUNC_MODE_CREATE)
+      mode_fopen = "wb";
+
+    return FileSystem::OpenCFile(static_cast<const char*>(filename), mode_fopen);
+  };
+
+  return unzOpen2_64(filename, &funcs);
+}
+
+} // namespace MinizipHelpers