zircon/system/ulib/ftl-mtd/ftl-volume-wrapper.cpp

// 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.

#include <lib/ftl-mtd/ftl-volume-wrapper.h>

namespace ftl_mtd {

zx_status_t FtlVolumeWrapper::Init(std::unique_ptr<ftl::NdmDriver> driver) {
    if (volume_->Init(std::move(driver)) != nullptr) {
        return ZX_ERR_IO;
    }
    return ZX_OK;
}

bool FtlVolumeWrapper::OnVolumeAdded(uint32_t page_size, uint32_t num_pages) {
    page_size_ = page_size;
    num_pages_ = num_pages;
    return true;
}

ssize_t FtlVolumeWrapper::Read(void* buffer, size_t count) {
    if (page_ >= num_pages_) {
        return 0;
    }

    if (count % page_size_ != 0) {
        return ZX_ERR_INVALID_ARGS;
    }

    uint32_t page_count = static_cast<uint32_t>(count / page_size_);
    zx_status_t status = volume_->Read(page_, page_count, buffer);
    if (status != ZX_OK) {
        return status;
    }

    page_ += page_count;
    return count;
}

ssize_t FtlVolumeWrapper::Write(void* buffer, size_t count) {
    if (page_ >= num_pages_) {
        return 0;
    }

    if (count % page_size_ != 0) {
        return ZX_ERR_INVALID_ARGS;
    }

    uint32_t page_count = static_cast<uint32_t>(count / page_size_);
    zx_status_t status = volume_->Write(page_, page_count, buffer);
    if (status != ZX_OK) {
        return status;
    }

    page_ += page_count;
    return count;
}

ssize_t FtlVolumeWrapper::Seek(off_t offset, int whence) {
    if (offset % page_size_ != 0) {
        return ZX_ERR_INVALID_ARGS;
    }

    off_t page_delta = static_cast<off_t>(offset / page_size_);
    off_t page;

    if (whence == SEEK_SET) {
        page = page_delta;
    } else if (whence == SEEK_END) {
        page = static_cast<off_t>(num_pages_) - page_delta;
    } else if (whence == SEEK_CUR) {
        page = static_cast<off_t>(page_) + page_delta;
    } else {
        return ZX_ERR_INVALID_ARGS;
    }

    uint32_t page_u32 = static_cast<uint32_t>(page);
    if (page != page_u32) {
        return ZX_ERR_OUT_OF_RANGE;
    }

    page_ = page_u32;
    return Tell();
}

ssize_t FtlVolumeWrapper::Size() {
    return page_size_ * num_pages_;
}

ssize_t FtlVolumeWrapper::Tell() {
    return page_size_ * page_;
}

zx_status_t FtlVolumeWrapper::Truncate(size_t size) {
    return ZX_ERR_NOT_SUPPORTED;
}

zx_status_t FtlVolumeWrapper::Sync() {
    return volume_->Flush();
}

zx_status_t FtlVolumeWrapper::Format() {
    return volume_->Format();
}

} // namespace ftl_mtd