d3660f9ded
ENV_OBJECT_DIRECT_IO_ENABLE, DEFAULT_OBJECT_DIRECT_IO_ENABLE, ENV_OBJECT_DIRECT_IO_THRESHOLD and DEFAULT_OBJECT_DIRECT_IO_THRESHOLD were never read anywhere in the workspace. The real O_DIRECT read path landed in PR #4365 uses RUSTFS_OBJECT_DIRECT_IO_READ_ENABLE / RUSTFS_OBJECT_DIRECT_IO_READ_THRESHOLD (crates/ecstore/src/disk/local.rs). Keeping the near-identically named dead knobs invites operators to set the wrong variable and believe O_DIRECT is enabled. Co-authored-by: heihutu <[email protected]>
59 lines
2.6 KiB
Rust
59 lines
2.6 KiB
Rust
// Copyright 2024 RustFS Team
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
//! Mmap-based read I/O configuration constants.
|
|
//!
|
|
//! This module defines environment variables and default values for mmap-based
|
|
//! read operations. Note: the legacy "zero_copy" env var is kept as a
|
|
//! deprecated compatibility alias; the actual implementation performs
|
|
//! mmap-then-copy, not true zero-copy.
|
|
|
|
// =============================================================================
|
|
// Mmap Read Configuration
|
|
// =============================================================================
|
|
|
|
/// Environment variable for mmap-based read enable.
|
|
///
|
|
/// When enabled, uses mmap (Unix) or optimized reads for file access.
|
|
/// This reduces memory copies from 3-4 to 1, lowering CPU usage and
|
|
/// improving latency for large object reads.
|
|
///
|
|
/// - Purpose: Enable or disable mmap-based read operations
|
|
/// - Acceptable values: `"true"` / `"false"` (case-insensitive) or a boolean typed config
|
|
/// - Semantics: When enabled, uses mmap on Unix systems for memory-mapped file reads;
|
|
/// falls back to regular I/O on non-Unix platforms or when mmap fails
|
|
/// - Example: `export RUSTFS_OBJECT_MMAP_READ_ENABLE=true`
|
|
pub const ENV_OBJECT_MMAP_READ_ENABLE: &str = "RUSTFS_OBJECT_MMAP_READ_ENABLE";
|
|
|
|
/// Deprecated compatibility alias for mmap-based read enable.
|
|
///
|
|
/// Prefer [`ENV_OBJECT_MMAP_READ_ENABLE`]. When both variables are set, the
|
|
/// canonical mmap-read variable takes precedence.
|
|
pub const ENV_OBJECT_ZERO_COPY_ENABLE: &str = "RUSTFS_OBJECT_ZERO_COPY_ENABLE";
|
|
|
|
/// Default: mmap-based reads are enabled.
|
|
///
|
|
/// Uses memory mapping (mmap) on Unix systems, then copies data into owned
|
|
/// Bytes. This is faster than multiple read+copy passes but is NOT true
|
|
/// zero-copy (the data is still copied once from the mmap region).
|
|
///
|
|
/// On non-Unix platforms or when mmap fails, the system automatically falls back
|
|
/// to regular I/O without errors.
|
|
pub const DEFAULT_OBJECT_MMAP_READ_ENABLE: bool = true;
|
|
|
|
/// Deprecated compatibility alias for mmap-based read default.
|
|
///
|
|
/// Prefer [`DEFAULT_OBJECT_MMAP_READ_ENABLE`].
|
|
pub const DEFAULT_OBJECT_ZERO_COPY_ENABLE: bool = DEFAULT_OBJECT_MMAP_READ_ENABLE;
|