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diff --git a/indra/llfilesystem/lldiskcache.h b/indra/llfilesystem/lldiskcache.h
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+++ b/indra/llfilesystem/lldiskcache.h
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+/**
+ * @file lldiskcache.h
+ * @brief Declaration SQLite meta data / file storage API
+ * @brief Declaration of the generic disk cache interface
+          as well the SQLite header/implementation.
+ * @Note  Eventually, this component might split into an interface
+ *        file and multiple implemtations but for now, this is the
+ *        only one so I think it's okay to combine everything. 
+ *
+ * $LicenseInfo:firstyear=2009&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2020, Linden Research, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#ifndef _LLDISKCACHE
+#define _LLDISKCACHE
+
+#include <iostream>
+#include <string>
+
+#include "sqlite3.h"
+
+// Enable this line to display each SQL statement when it is executed
+// It can lead to a lot of spam but useful for debugging
+//#define SHOW_STATEMENTS
+
+// I toyed with the idea of a variety of approaches and thought have
+// an abstract base class with which to hang different implementations
+// off was a good idea but I think we settled on a single approach
+// so I will likely remove this level of indirection if not other 
+// interesting implementation ideas present themselves.
+class llDiskCacheBase
+{
+    public:
+        llDiskCacheBase() {};
+        virtual ~llDiskCacheBase() {};
+        virtual bool open(const std::string db_folder,
+                          const std::string db_filename) = 0;
+        virtual bool exists(const std::string id, bool& exists) = 0;
+        virtual bool put(const std::string id,
+                         char* binary_data,
+                         int binary_data_size) = 0;
+        virtual const bool get(const std::string id,
+                               char** mem_buffer,
+                               int& mem_buffer_size) = 0;
+        virtual bool purge(int num_entries) = 0;
+        virtual void close() = 0;
+        virtual const std::string dbVersion() = 0;
+        virtual const std::string getFilenameById(const std::string id) = 0;
+        virtual const int getAccessCountById(const std::string id) = 0;
+        virtual void getNumEntries(int& num_entries, int& max_entries) = 0;
+};
+
+// implementation for the SQLite/disk blended case
+// see source file for detailed comments
+class llDiskCache :
+    public llDiskCacheBase
+{
+    public:
+        llDiskCache();
+        virtual ~llDiskCache();
+        virtual bool open(const std::string db_folder,
+                          const std::string db_filename) override;
+        virtual bool exists(const std::string id, bool& exists) override;
+        virtual bool put(const std::string id,
+                         char* binary_data,
+                         int binary_data_size) override;
+        virtual const bool get(const std::string id,
+                               char** mem_buffer,
+                               int& mem_buffer_size) override;
+        virtual bool purge(int num_entries) override;
+        virtual void close() override;
+        virtual const std::string dbVersion() override;
+        virtual const std::string getFilenameById(const std::string id) override;
+        virtual const int getAccessCountById(const std::string id) override;
+        virtual void getNumEntries(int& num_entries, int& max_entries) override;
+
+    private:
+        sqlite3* mDb;
+        std::string mDataStorePath;
+        const std::string mTableName = "lldiskcache";
+        const std::string mIdFieldName = "id";
+        const std::string mFilenameFieldName = "filename";
+        const std::string mFilesizeFieldName = "filesize";
+        const std::string mInsertionDateTimeFieldName = "insert_datetime";
+        const std::string mLastAccessDateTimeFieldName = "last_access_datetime";
+        const std::string mAccessCountFieldName = "access_count";
+
+    private:
+        void printError(const std::string funcname,
+                        const std::string desc,
+                        bool is_sqlite_err);
+        bool beginTransaction();
+        bool endTransaction();
+        std::string makeUniqueFilename();
+        const std::string systemSeparator();
+        const std::string makeFullPath(const std::string filename);
+        bool sqliteExec(const std::string stmt,
+                        const std::string funcname);
+        sqlite3_stmt* sqlitePrepareStep(const std::string funcname,
+                                        const std::string stmt,
+                                        int sqlite_success_condition);
+        const std::string sqlComposeCreateTable();
+        const std::string sqlComposeExists(const std::string id);
+        const std::string sqlComposePut(const std::string id,
+                                        const std::string filename,
+                                        int binary_data_size);
+        const std::string sqlComposeGetSelect(const std::string id);
+        const std::string sqlComposeGetUpdate(const std::string id);
+        const std::string sqlComposePurge(int num_entries);
+};
+
+#endif // _LLDISKCACHE