Struct PromptLogger 

pub struct PromptLogger { /* private fields */ }

Best-effort rolling JSONL writer.

Why: hook commands are short-lived (one entry per invocation), so the logger is constructed at the start of the invocation, writes one line, and drops at the end. There is no daemon path involved; cross-process concurrency is handled by OpenOptions::append(true) which O_APPEND atomically positions each write at end-of-file on POSIX. On Windows (not a target for this crate) the same flag delivers similar guarantees for writes under the 4 KiB pipe-atomicity threshold, which our JSONL lines comfortably fit under. What: holds an immutable PromptLogConfig. log resolves the active filename (date + numeric suffix that fits under max_bytes), opens the file in append mode, writes one line, then closes it. Every failure path is a tracing::warn! to stderr; the caller never observes an error. Test: single_event_roundtrip, rotation_at_size_cap, retention_prunes_old_files, disabled_mode_writes_nothing, hash_mode_hashes_trigger_prompt.

Implementations

impl PromptLogger

pub fn from_env() -> Self

Build a logger from the configured data_root and process env vars.

Why: keeps the call site in prompt_context.rs / inbox_check.rs to a single line and centralises the env-parsing rules. What: resolves <data_root> via trusty_common::resolve_data_dir using the canonical trusty-memory app name, then layers env overrides via PromptLogConfig::from_env_with_root. Returns a disabled logger when the data dir cannot be resolved — the caller proceeds normally. Test: covered indirectly by the integration tests.

pub fn from_config(config: PromptLogConfig) -> Self

Build a logger from an explicit config (test injection point).

Why: integration / unit tests want to pin a tempdir without polluting process env. Same shape as from_env, different injection. Test: every unit test in this module.

pub fn config(&self) -> &PromptLogConfig

Active configuration (for tests / diagnostics).

pub fn log(&self, entry: PromptLogEntry)

Append one entry to the active log file.

Why: the public API surface — exactly one call per hook invocation. Best-effort by contract. What: short-circuits when enabled = false; otherwise computes the active filename (creating the directory and pruning stale files as needed), serialises the entry to a single JSON line, and appends it. Any failure (mkdir, open, write, serde) is downgraded to a tracing::warn! and discarded. Test: see module-level tests.

Trait Implementations

impl Clone for PromptLogger

fn clone(&self) -> PromptLogger

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PromptLogger

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.