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// SPDX-License-Identifier: Apache-2.0
//! [`LiteConfig::from_env`] — environment-variable overrides.
//!
//! Every variable is optional and independently applied: an absent or
//! malformed value leaves the corresponding default in place and logs a
//! warning rather than failing the open.
use super::types::LiteConfig;
impl LiteConfig {
/// Load configuration from environment variables, falling back to defaults
/// for any variable that is absent or malformed.
///
/// Handled variables:
/// - `NODEDB_LITE_MEMORY_MB` — total memory budget in mebibytes (parsed as `usize`)
/// - `NODEDB_LITE_AUTO_FLUSH_MS` — auto-flush interval in milliseconds (parsed as `u64`;
/// 0 = disabled)
/// - `NODEDB_LITE_AUTO_COMPACT_MS` — auto-compact interval in milliseconds (parsed as `u64`;
/// 0 = disabled, the default)
/// - `NODEDB_LITE_OUTBOUND_QUEUE_CAP` — max pending entries per durable outbound queue
/// (parsed as `usize`; must be > 0)
pub fn from_env() -> Self {
let mut cfg = Self::default();
if let Ok(val) = std::env::var("NODEDB_LITE_MEMORY_MB") {
match val.trim().parse::<usize>() {
Ok(mb) => {
let bytes = mb.saturating_mul(1024 * 1024);
tracing::info!(
env_var = "NODEDB_LITE_MEMORY_MB",
value = mb,
bytes,
"environment variable override applied"
);
cfg.memory_budget = bytes;
}
Err(_) => {
tracing::warn!(
env_var = "NODEDB_LITE_MEMORY_MB",
value = %val,
"ignoring malformed environment variable (expected unsigned integer), \
using default 100 MiB"
);
}
}
}
if let Ok(val) = std::env::var("NODEDB_LITE_OUTBOUND_QUEUE_CAP") {
match val.trim().parse::<usize>() {
Ok(cap) if cap > 0 => {
tracing::info!(
env_var = "NODEDB_LITE_OUTBOUND_QUEUE_CAP",
value = cap,
"environment variable override applied"
);
cfg.outbound_queue_cap = cap;
}
Ok(_) => {
tracing::warn!(
env_var = "NODEDB_LITE_OUTBOUND_QUEUE_CAP",
"value must be > 0; using default 100_000"
);
}
Err(_) => {
tracing::warn!(
env_var = "NODEDB_LITE_OUTBOUND_QUEUE_CAP",
value = %val,
"ignoring malformed environment variable (expected unsigned integer), \
using default 100_000"
);
}
}
}
if let Ok(val) = std::env::var("NODEDB_LITE_AUTO_FLUSH_MS") {
match val.trim().parse::<u64>() {
Ok(ms) => {
tracing::info!(
env_var = "NODEDB_LITE_AUTO_FLUSH_MS",
value = ms,
"environment variable override applied"
);
cfg.auto_flush_ms = ms;
}
Err(_) => {
tracing::warn!(
env_var = "NODEDB_LITE_AUTO_FLUSH_MS",
value = %val,
"ignoring malformed environment variable (expected unsigned integer), \
using default 1000 ms"
);
}
}
}
if let Ok(val) = std::env::var("NODEDB_LITE_AUTO_COMPACT_MS") {
match val.trim().parse::<u64>() {
Ok(ms) => {
tracing::info!(
env_var = "NODEDB_LITE_AUTO_COMPACT_MS",
value = ms,
"environment variable override applied"
);
cfg.auto_compact_ms = ms;
}
Err(_) => {
tracing::warn!(
env_var = "NODEDB_LITE_AUTO_COMPACT_MS",
value = %val,
"ignoring malformed environment variable (expected unsigned integer), \
using default 0 (disabled)"
);
}
}
}
cfg
}
}
#[cfg(test)]
mod tests {
use super::*;
/// All `from_env` cases run sequentially in one test to avoid parallel
/// env-var mutation across threads (no `serial_test` dependency needed).
#[test]
fn from_env_all_cases() {
// Use a mutex so if other test files ever share this process they
// cannot race on the env var.
static ENV_LOCK: std::sync::Mutex<()> = std::sync::Mutex::new(());
let _guard = ENV_LOCK.lock().unwrap_or_else(|e| e.into_inner());
// SAFETY: we hold ENV_LOCK and are the only thread touching this var.
// Case 1: var absent → default.
unsafe { std::env::remove_var("NODEDB_LITE_MEMORY_MB") };
let cfg = LiteConfig::from_env();
assert_eq!(
cfg.memory_budget,
100 * 1024 * 1024,
"absent var should give default 100 MiB"
);
// Case 2: valid integer → applied.
unsafe { std::env::set_var("NODEDB_LITE_MEMORY_MB", "256") };
let cfg = LiteConfig::from_env();
assert_eq!(
cfg.memory_budget,
256 * 1024 * 1024,
"256 MiB should be applied"
);
// Case 3: malformed → fallback to default.
unsafe { std::env::set_var("NODEDB_LITE_MEMORY_MB", "not_a_number") };
let cfg = LiteConfig::from_env();
assert_eq!(
cfg.memory_budget,
100 * 1024 * 1024,
"malformed var should fall back to default"
);
// Case 4: whitespace-padded integer → trimmed and applied.
unsafe { std::env::set_var("NODEDB_LITE_MEMORY_MB", " 512 ") };
let cfg = LiteConfig::from_env();
assert_eq!(
cfg.memory_budget,
512 * 1024 * 1024,
"padded value should be trimmed and applied"
);
// Cleanup.
unsafe { std::env::remove_var("NODEDB_LITE_MEMORY_MB") };
// NODEDB_LITE_AUTO_FLUSH_MS cases.
// Case A: var absent → default 1000.
unsafe { std::env::remove_var("NODEDB_LITE_AUTO_FLUSH_MS") };
let cfg = LiteConfig::from_env();
assert_eq!(
cfg.auto_flush_ms, 1_000,
"absent var should give default 1000 ms"
);
// Case B: valid integer → applied.
unsafe { std::env::set_var("NODEDB_LITE_AUTO_FLUSH_MS", "500") };
let cfg = LiteConfig::from_env();
assert_eq!(cfg.auto_flush_ms, 500, "500 ms should be applied");
// Case C: 0 = disabled.
unsafe { std::env::set_var("NODEDB_LITE_AUTO_FLUSH_MS", "0") };
let cfg = LiteConfig::from_env();
assert_eq!(cfg.auto_flush_ms, 0, "0 should disable auto-flush");
// Case D: malformed → fallback to default.
unsafe { std::env::set_var("NODEDB_LITE_AUTO_FLUSH_MS", "not_a_number") };
let cfg = LiteConfig::from_env();
assert_eq!(
cfg.auto_flush_ms, 1_000,
"malformed var should fall back to default 1000 ms"
);
// Cleanup.
unsafe { std::env::remove_var("NODEDB_LITE_AUTO_FLUSH_MS") };
// NODEDB_LITE_AUTO_COMPACT_MS cases.
// Case A: var absent → default 0 (disabled).
unsafe { std::env::remove_var("NODEDB_LITE_AUTO_COMPACT_MS") };
let cfg = LiteConfig::from_env();
assert_eq!(
cfg.auto_compact_ms, 0,
"absent var should give default 0 (disabled)"
);
// Case B: valid integer → applied.
unsafe { std::env::set_var("NODEDB_LITE_AUTO_COMPACT_MS", "300000") };
let cfg = LiteConfig::from_env();
assert_eq!(cfg.auto_compact_ms, 300_000, "300000 ms should be applied");
// Case C: malformed → fallback to default 0.
unsafe { std::env::set_var("NODEDB_LITE_AUTO_COMPACT_MS", "not_a_number") };
let cfg = LiteConfig::from_env();
assert_eq!(
cfg.auto_compact_ms, 0,
"malformed var should fall back to default 0"
);
// Cleanup.
unsafe { std::env::remove_var("NODEDB_LITE_AUTO_COMPACT_MS") };
}
}