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// Copyright 2025 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef NET_DISK_CACHE_SQL_SQL_BACKEND_CONSTANTS_H_
#define NET_DISK_CACHE_SQL_SQL_BACKEND_CONSTANTS_H_
#include <cstdint>
#include <string_view>
#include "base/files/file_path.h"
namespace disk_cache {
// This constant defines the denominator for the maximum fraction of the cache
// that a single entry can consume. For example, if this value is 8, a single
// entry can consume at most 1/8th of the total cache size.
// Maximum fraction of the cache that one entry can consume.
inline constexpr int kSqlBackendMaxFileRatioDenominator = 8;
// A maximum file size when the overall cache size is very small, meaning there
// is very little free disk space.
inline constexpr int64_t kSqlBackendMinFileSizeLimit = 5 * 1024 * 1024;
// Keys for the key-value pairs stored in the `meta` table.
inline constexpr std::string_view kSqlBackendMetaTableKeyEntryCount =
"EntryCount";
inline constexpr std::string_view kSqlBackendMetaTableKeyTotalSize =
"TotalSize";
inline constexpr base::FilePath::CharType kSqlBackendDatabaseFileName[] =
FILE_PATH_LITERAL("sqldb");
// The oldest database schema version that the current code can read.
// A database with a version older than this will be razed as it's considered
// obsolete and the code no longer supports migrating from it.
inline constexpr int kSqlBackendLowestSupportedDatabaseVersion = 1;
// The current version of the database schema. This should be incremented for
// any schema change.
inline constexpr int kSqlBackendCurrentDatabaseVersion = 1;
// The oldest application version that can use a database with the current
// schema. If a schema change is not backward-compatible, this must be set to
// the same value as `kSqlBackendCurrentDatabaseVersion`.
inline constexpr int kSqlBackendCompatibleDatabaseVersion = 1;
// Estimated static size overhead for a resource entry in the database,
// excluding the key and any blob data. This is a conservative estimate based on
// empirical testing and is intended to account for the overhead of the row in
// the `resources` table, SQLite's B-tree overhead per entry, and other
// miscellaneous metadata. The
// `SqlPersistentStoreTest.StaticResourceSizeEstimation` test provides a basic
// validation of this constant against the actual file size.
// TODO(crbug.com/422065015): Re-evaluate this constant when head and body
// writing is implemented and new indexes are added, as the storage pattern may
// affect overhead.
inline constexpr int kSqlBackendStaticResourceSize = 100;
} // namespace disk_cache
#endif // NET_DISK_CACHE_SQL_SQL_BACKEND_CONSTANTS_H_
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