From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 21:33:14 +0200
Subject: Adding upstream version 115.7.0esr.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 storage/ReadOnlyNoLockVFS.cpp | 130 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 130 insertions(+)
 create mode 100644 storage/ReadOnlyNoLockVFS.cpp

(limited to 'storage/ReadOnlyNoLockVFS.cpp')

diff --git a/storage/ReadOnlyNoLockVFS.cpp b/storage/ReadOnlyNoLockVFS.cpp
new file mode 100644
index 0000000000..9a820085ed
--- /dev/null
+++ b/storage/ReadOnlyNoLockVFS.cpp
@@ -0,0 +1,130 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This VFS is built on top of the (unix|win32)-none, but it additionally
+ * sets any opened file as immutable, that allows to also open in read-only
+ * mode databases using WAL, or other journals that need auxiliary files, when
+ * such files cannot be created.
+ * This is useful when trying to read from third-party databases, avoiding any
+ * risk of creating auxiliary files (e.g. journals).
+ * It can only be used on read-only connections, because being a no-lock VFS
+ * it would be trivial to corrupt the data.
+ */
+
+#include "nsDebug.h"
+#include "sqlite3.h"
+
+#define ORIGVFS(p) ((sqlite3_vfs*)((p)->pAppData))
+
+#if defined(XP_WIN)
+#  define BASE_VFS "win32-none"
+#else
+#  define BASE_VFS "unix-none"
+#endif
+
+#define VFS_NAME "readonly-immutable-nolock"
+
+namespace {
+
+static int vfsOpen(sqlite3_vfs* vfs, const char* zName, sqlite3_file* pFile,
+                   int flags, int* pOutFlags) {
+  if ((flags & SQLITE_OPEN_READONLY) == 0) {
+    // This is not done to be used in readwrite connections.
+    return SQLITE_CANTOPEN;
+  }
+
+  sqlite3_vfs* pOrigVfs = ORIGVFS(vfs);
+  int rc = pOrigVfs->xOpen(pOrigVfs, zName, pFile, flags, pOutFlags);
+  if (rc != SQLITE_OK) {
+    return rc;
+  }
+
+  const sqlite3_io_methods* pOrigMethods = pFile->pMethods;
+
+  // If the IO version is higher than the last known one, you should update
+  // this IO adding appropriate methods for any methods added in the version
+  // change.
+  MOZ_ASSERT(pOrigMethods->iVersion <= 3);
+
+  static const sqlite3_io_methods vfs_io_methods = {
+      pOrigMethods->iVersion,           /* iVersion */
+      pOrigMethods->xClose,             /* xClose */
+      pOrigMethods->xRead,              /* xRead */
+      pOrigMethods->xWrite,             /* xWrite */
+      pOrigMethods->xTruncate,          /* xTruncate */
+      pOrigMethods->xSync,              /* xSync */
+      pOrigMethods->xFileSize,          /* xFileSize */
+      pOrigMethods->xLock,              /* xLock */
+      pOrigMethods->xUnlock,            /* xUnlock */
+      pOrigMethods->xCheckReservedLock, /* xCheckReservedLock */
+      pOrigMethods->xFileControl,       /* xFileControl */
+      pOrigMethods->xSectorSize,        /* xSectorSize */
+      [](sqlite3_file*) {
+        return SQLITE_IOCAP_IMMUTABLE;
+      },                         /* xDeviceCharacteristics */
+      pOrigMethods->xShmMap,     /* xShmMap */
+      pOrigMethods->xShmLock,    /* xShmLock */
+      pOrigMethods->xShmBarrier, /* xShmBarrier */
+      pOrigMethods->xShmUnmap,   /* xShmUnmap */
+      pOrigMethods->xFetch,      /* xFetch */
+      pOrigMethods->xUnfetch     /* xUnfetch */
+  };
+  pFile->pMethods = &vfs_io_methods;
+  if (pOutFlags) {
+    *pOutFlags = flags;
+  }
+
+  return SQLITE_OK;
+}
+
+}  // namespace
+
+namespace mozilla::storage {
+
+UniquePtr<sqlite3_vfs> ConstructReadOnlyNoLockVFS() {
+  if (sqlite3_vfs_find(VFS_NAME) != nullptr) {
+    return nullptr;
+  }
+  sqlite3_vfs* pOrigVfs = sqlite3_vfs_find(BASE_VFS);
+  if (!pOrigVfs) {
+    return nullptr;
+  }
+
+  // If the VFS version is higher than the last known one, you should update
+  // this VFS adding appropriate methods for any methods added in the version
+  // change.
+  MOZ_ASSERT(pOrigVfs->iVersion <= 3);
+
+  static const sqlite3_vfs vfs = {
+      pOrigVfs->iVersion,          /* iVersion  */
+      pOrigVfs->szOsFile,          /* szOsFile */
+      pOrigVfs->mxPathname,        /* mxPathname */
+      nullptr,                     /* pNext */
+      VFS_NAME,                    /* zName */
+      pOrigVfs,                    /* pAppData */
+      vfsOpen,                     /* xOpen */
+      pOrigVfs->xDelete,           /* xDelete */
+      pOrigVfs->xAccess,           /* xAccess */
+      pOrigVfs->xFullPathname,     /* xFullPathname */
+      pOrigVfs->xDlOpen,           /* xDlOpen */
+      pOrigVfs->xDlError,          /* xDlError */
+      pOrigVfs->xDlSym,            /* xDlSym */
+      pOrigVfs->xDlClose,          /* xDlClose */
+      pOrigVfs->xRandomness,       /* xRandomness */
+      pOrigVfs->xSleep,            /* xSleep */
+      pOrigVfs->xCurrentTime,      /* xCurrentTime */
+      pOrigVfs->xGetLastError,     /* xGetLastError */
+      pOrigVfs->xCurrentTimeInt64, /* xCurrentTimeInt64 */
+      pOrigVfs->xSetSystemCall,    /* xSetSystemCall */
+      pOrigVfs->xGetSystemCall,    /* xGetSystemCall */
+      pOrigVfs->xNextSystemCall    /* xNextSystemCall */
+  };
+
+  return MakeUnique<sqlite3_vfs>(vfs);
+}
+
+}  // namespace mozilla::storage
-- 
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