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-rw-r--r--storage/FileSystemModule.cpp304
1 files changed, 304 insertions, 0 deletions
diff --git a/storage/FileSystemModule.cpp b/storage/FileSystemModule.cpp
new file mode 100644
index 000000000..ed2f8cdef
--- /dev/null
+++ b/storage/FileSystemModule.cpp
@@ -0,0 +1,304 @@
+/* -*- 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/. */
+
+#include "FileSystemModule.h"
+
+#include "sqlite3.h"
+#include "nsString.h"
+#include "nsISimpleEnumerator.h"
+#include "nsIFile.h"
+
+namespace {
+
+struct VirtualTableCursorBase
+{
+ VirtualTableCursorBase()
+ {
+ memset(&mBase, 0, sizeof(mBase));
+ }
+
+ sqlite3_vtab_cursor mBase;
+};
+
+struct VirtualTableCursor : public VirtualTableCursorBase
+{
+public:
+ VirtualTableCursor()
+ : mRowId(-1)
+ {
+ mCurrentFileName.SetIsVoid(true);
+ }
+
+ const nsString& DirectoryPath() const
+ {
+ return mDirectoryPath;
+ }
+
+ const nsString& CurrentFileName() const
+ {
+ return mCurrentFileName;
+ }
+
+ int64_t RowId() const
+ {
+ return mRowId;
+ }
+
+ nsresult Init(const nsAString& aPath);
+ nsresult NextFile();
+
+private:
+ nsCOMPtr<nsISimpleEnumerator> mEntries;
+
+ nsString mDirectoryPath;
+ nsString mCurrentFileName;
+
+ int64_t mRowId;
+};
+
+nsresult
+VirtualTableCursor::Init(const nsAString& aPath)
+{
+ nsCOMPtr<nsIFile> directory =
+ do_CreateInstance(NS_LOCAL_FILE_CONTRACTID);
+ NS_ENSURE_TRUE(directory, NS_ERROR_FAILURE);
+
+ nsresult rv = directory->InitWithPath(aPath);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ rv = directory->GetPath(mDirectoryPath);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ rv = directory->GetDirectoryEntries(getter_AddRefs(mEntries));
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ rv = NextFile();
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ return NS_OK;
+}
+
+nsresult
+VirtualTableCursor::NextFile()
+{
+ bool hasMore;
+ nsresult rv = mEntries->HasMoreElements(&hasMore);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ if (!hasMore) {
+ mCurrentFileName.SetIsVoid(true);
+ return NS_OK;
+ }
+
+ nsCOMPtr<nsISupports> entry;
+ rv = mEntries->GetNext(getter_AddRefs(entry));
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ nsCOMPtr<nsIFile> file = do_QueryInterface(entry);
+ NS_ENSURE_TRUE(file, NS_ERROR_FAILURE);
+
+ rv = file->GetLeafName(mCurrentFileName);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ mRowId++;
+
+ return NS_OK;
+}
+
+int Connect(sqlite3* aDB, void* aAux, int aArgc, const char* const* aArgv,
+ sqlite3_vtab** aVtab, char** aErr)
+{
+ static const char virtualTableSchema[] =
+ "CREATE TABLE fs ("
+ "name TEXT, "
+ "path TEXT"
+ ")";
+
+ int rc = sqlite3_declare_vtab(aDB, virtualTableSchema);
+ if (rc != SQLITE_OK) {
+ return rc;
+ }
+
+ sqlite3_vtab* vt = new sqlite3_vtab();
+ memset(vt, 0, sizeof(*vt));
+
+ *aVtab = vt;
+
+ return SQLITE_OK;
+}
+
+int Disconnect(sqlite3_vtab* aVtab )
+{
+ delete aVtab;
+
+ return SQLITE_OK;
+}
+
+int BestIndex(sqlite3_vtab* aVtab, sqlite3_index_info* aInfo)
+{
+ // Here we specify what index constraints we want to handle. That is, there
+ // might be some columns with particular constraints in which we can help
+ // SQLite narrow down the result set.
+ //
+ // For example, take the "path = x" where x is a directory. In this case,
+ // we can narrow our search to just this directory instead of the entire file
+ // system. This can be a significant optimization. So, we want to handle that
+ // constraint. To do so, we would look for two specific input conditions:
+ //
+ // 1. aInfo->aConstraint[i].iColumn == 1
+ // 2. aInfo->aConstraint[i].op == SQLITE_INDEX_CONSTRAINT_EQ
+ //
+ // The first states that the path column is being used in one of the input
+ // constraints and the second states that the constraint involves the equal
+ // operator.
+ //
+ // An even more specific search would be for name='xxx', in which case we
+ // can limit the search to a single file, if it exists.
+ //
+ // What we have to do here is look for all of our index searches and select
+ // the narrowest. We can only pick one, so obviously we want the one that
+ // is the most specific, which leads to the smallest result set.
+
+ for(int i = 0; i < aInfo->nConstraint; i++) {
+ if (aInfo->aConstraint[i].iColumn == 1 && aInfo->aConstraint[i].usable) {
+ if (aInfo->aConstraint[i].op & SQLITE_INDEX_CONSTRAINT_EQ) {
+ aInfo->aConstraintUsage[i].argvIndex = 1;
+ }
+ break;
+ }
+
+ // TODO: handle single files (constrained also by the name column)
+ }
+
+ return SQLITE_OK;
+}
+
+int Open(sqlite3_vtab* aVtab, sqlite3_vtab_cursor** aCursor)
+{
+ VirtualTableCursor* cursor = new VirtualTableCursor();
+
+ *aCursor = reinterpret_cast<sqlite3_vtab_cursor*>(cursor);
+
+ return SQLITE_OK;
+}
+
+int Close(sqlite3_vtab_cursor* aCursor)
+{
+ VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
+
+ delete cursor;
+
+ return SQLITE_OK;
+}
+
+int Filter(sqlite3_vtab_cursor* aCursor, int aIdxNum, const char* aIdxStr,
+ int aArgc, sqlite3_value** aArgv)
+{
+ VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
+
+ if(aArgc <= 0) {
+ return SQLITE_OK;
+ }
+
+ nsDependentString path(
+ reinterpret_cast<const char16_t*>(::sqlite3_value_text16(aArgv[0])));
+
+ nsresult rv = cursor->Init(path);
+ NS_ENSURE_SUCCESS(rv, SQLITE_ERROR);
+
+ return SQLITE_OK;
+}
+
+int Next(sqlite3_vtab_cursor* aCursor)
+{
+ VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
+
+ nsresult rv = cursor->NextFile();
+ NS_ENSURE_SUCCESS(rv, SQLITE_ERROR);
+
+ return SQLITE_OK;
+}
+
+int Eof(sqlite3_vtab_cursor* aCursor)
+{
+ VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
+ return cursor->CurrentFileName().IsVoid() ? 1 : 0;
+}
+
+int Column(sqlite3_vtab_cursor* aCursor, sqlite3_context* aContext,
+ int aColumnIndex)
+{
+ VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
+
+ switch (aColumnIndex) {
+ // name
+ case 0: {
+ const nsString& name = cursor->CurrentFileName();
+ sqlite3_result_text16(aContext, name.get(),
+ name.Length() * sizeof(char16_t),
+ SQLITE_TRANSIENT);
+ break;
+ }
+
+ // path
+ case 1: {
+ const nsString& path = cursor->DirectoryPath();
+ sqlite3_result_text16(aContext, path.get(),
+ path.Length() * sizeof(char16_t),
+ SQLITE_TRANSIENT);
+ break;
+ }
+ default:
+ NS_NOTREACHED("Unsupported column!");
+ }
+
+ return SQLITE_OK;
+}
+
+int RowId(sqlite3_vtab_cursor* aCursor, sqlite3_int64* aRowid)
+{
+ VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
+
+ *aRowid = cursor->RowId();
+
+ return SQLITE_OK;
+}
+
+} // namespace
+
+namespace mozilla {
+namespace storage {
+
+int RegisterFileSystemModule(sqlite3* aDB, const char* aName)
+{
+ static sqlite3_module module = {
+ 1,
+ Connect,
+ Connect,
+ BestIndex,
+ Disconnect,
+ Disconnect,
+ Open,
+ Close,
+ Filter,
+ Next,
+ Eof,
+ Column,
+ RowId,
+ nullptr,
+ nullptr,
+ nullptr,
+ nullptr,
+ nullptr,
+ nullptr,
+ nullptr
+ };
+
+ return sqlite3_create_module(aDB, aName, &module, nullptr);
+}
+
+} // namespace storage
+} // namespace mozilla