// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef ZIRCON_SYSTEM_ULIB_STORAGE_METRICS_FS_METRICS_H_
#define ZIRCON_SYSTEM_ULIB_STORAGE_METRICS_FS_METRICS_H_

#include <atomic>
#include <stdio.h>

#include <fbl/macros.h>
#include <fuchsia/minfs/c/fidl.h>
#include <storage-metrics/storage-metrics.h>

namespace storage_metrics {
using storage_metrics::Metrics;

// FsMetrics is common metrics that can be used across filesystems. The members
// are internded to stay generic.
class FsMetrics : public Metrics {
public:
    DISALLOW_COPY_ASSIGN_AND_MOVE(FsMetrics);

    FsMetrics() = default;
    explicit FsMetrics(const fuchsia_storage_metrics_FsMetrics* metrics);
    ~FsMetrics() = default;

    // Copies to fields of fidl structure the corresponding fields of FsMetrics.
    void CopyToFidl(fuchsia_storage_metrics_FsMetrics* metrics) const;

    // Prints all CallStat fields to file |stream|. Passes |success| to
    // CallStat::Dump. See CallStat::Dump.
    void Dump(FILE* stream, std::optional<bool> success = std::nullopt) const;

    // Following Updata*Stat functions take |success|, which denotes whether the
    // call was successful or not, |delta_time| is the time takes complete the call
    // and bytes transferred
    //   On success, bytes transferred is number bytes returned to caller. It is
    //     NOT the number of bytes fetched from underlying subsystem and it
    //     is NOT number of bytes requested by the caller.
    //   On failure, bytes_transferred is the number of bytes requested by the
    //     caller.
    void UpdateCreateStat(bool success, zx_ticks_t delta_time, uint64_t bytes_transferred) {
        if (Enabled() == false) {
            return;
        }
        create_.UpdateCallStat(success, delta_time, bytes_transferred);
    }

    void UpdateReadStat(bool success, zx_ticks_t delta_time, uint64_t bytes_transferred) {
        if (Enabled() == false) {
            return;
        }
        read_.UpdateCallStat(success, delta_time, bytes_transferred);
    }

    void UpdateWriteStat(bool success, zx_ticks_t delta_time, uint64_t bytes_transferred) {
        if (Enabled() == false) {
            return;
        }
        write_.UpdateCallStat(success, delta_time, bytes_transferred);
    }

    void UpdateTruncateStat(bool success, zx_ticks_t delta_time, uint64_t bytes_transferred) {
        if (Enabled() == false) {
            return;
        }
        truncate_.UpdateCallStat(success, delta_time, bytes_transferred);
    }

    void UpdateUnlinkStat(bool success, zx_ticks_t delta_time, uint64_t bytes_transferred) {
        if (Enabled() == false) {
            return;
        }
        unlink_.UpdateCallStat(success, delta_time, bytes_transferred);
    }

    void UpdateRenameStat(bool success, zx_ticks_t delta_time, uint64_t bytes_transferred) {
        if (Enabled() == false) {
            return;
        }
        rename_.UpdateCallStat(success, delta_time, bytes_transferred);
    }

    void UpdateLookupStat(bool success, zx_ticks_t delta_time, uint64_t bytes_transferred) {
        if (Enabled() == false) {
            return;
        }
        lookup_.UpdateCallStat(success, delta_time, bytes_transferred);
    }

    void UpdateOpenStat(bool success, zx_ticks_t delta_time, uint64_t bytes_transferred) {
        if (Enabled() == false) {
            return;
        }
        open_.UpdateCallStat(success, delta_time, bytes_transferred);
    }

private:
    CallStat create_ = {};   // stats for create
    CallStat read_ = {};     // stats for read
    CallStat write_ = {};    // stats for write
    CallStat truncate_ = {}; // stats for truncate
    CallStat unlink_ = {};   // stats for unlink
    CallStat rename_ = {};   // stats for rename
    CallStat lookup_ = {};   // stats for lookup
    CallStat open_ = {};     // stats for open
};

} // namespace storage_metrics
#endif // ZIRCON_SYSTEM_ULIB_STORAGE_METRICS_FS_METRICS_H_