timeseries-table-format 0.3.0

Append-only time-series table format with gap/overlap tracking
Documentation 
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//! On-disk layout helpers for a table root.
//!
//! This module centralizes all *relative* path conventions under a table root:
//! - transaction log directory / commit file naming (`_timeseries_log/`)
//! - coverage sidecar directories (`_coverage/`)
//! - conventional data directory (`data/`)
//!
//! The functions here return relative [`std::path::PathBuf`] values. Callers are
//! expected to join these with a table root (for example, a
//! [`crate::storage::TableLocation`] / backend root) before doing IO.

use std::path::PathBuf;

// Coverage layout lives under `coverage/` but is re-exported here for convenience
// and to keep older imports compiling.
pub use crate::coverage::layout::{
    COVERAGE_EXT, COVERAGE_ROOT_DIR, CoverageLayoutError, SEGMENT_COVERAGE_DIR, TABLE_SNAPSHOT_DIR,
    segment_coverage_id_v1, segment_coverage_path, table_coverage_id_v1, table_snapshot_path,
    validate_coverage_id,
};

// ====================
// Data layout
// ====================

/// Conventional directory where segment files are stored (v0.1 default).
pub const DATA_DIR_NAME: &str = "data";

/// Relative path: `data/`
pub fn data_rel_dir() -> PathBuf {
    PathBuf::from(DATA_DIR_NAME)
}

// ====================
// Transaction log layout
// ====================

/// Name of the subdirectory containing the commit log.
pub const LOG_DIR_NAME: &str = "_timeseries_log";

/// Name of the file that stores the current version pointer.
pub const CURRENT_FILE_NAME: &str = "CURRENT";

/// Number of digits used in zero-padded commit file names.
pub const COMMIT_FILENAME_DIGITS: usize = 10;

/// Relative path: `_timeseries_log/`
pub fn log_rel_dir() -> PathBuf {
    PathBuf::from(LOG_DIR_NAME)
}

/// Relative path: `_timeseries_log/CURRENT`
pub fn current_rel_path() -> PathBuf {
    log_rel_dir().join(CURRENT_FILE_NAME)
}

/// Relative path: `_timeseries_log/<zero-padded>.json`
pub fn commit_rel_path(version: u64) -> PathBuf {
    let file_name = format!("{:0width$}.json", version, width = COMMIT_FILENAME_DIGITS);
    log_rel_dir().join(file_name)
}