Struct CacheManager 

pub struct CacheManager {
    pub cache_dir: PathBuf,
    pub offline: bool,
    /* private fields */
}

Downloads and caches MTGJSON data files from the CDN.

Checks Meta.json for version changes and re-downloads when stale. Individual files are downloaded lazily on first access.

Fields

cache_dir: PathBuf

Directory where cached files are stored.

offline: bool

If true, never download from CDN (use cached files only).

Implementations

impl CacheManager

pub fn new( cache_dir: Option<PathBuf>, offline: bool, timeout: Duration, on_progress: Option<ProgressCallback>, ) -> Result<Self>

Create a new cache manager.

If cache_dir is None, uses the platform-appropriate default cache directory. Creates the cache directory if it does not exist.

pub fn client(&mut self) -> &Client

Lazy HTTP client, created on first use.

pub fn remote_version(&mut self) -> Result<Option<String>>

Fetch the current MTGJSON version from Meta.json on the CDN.

Returns the version string (e.g. "5.2.2+20240101"), or None if offline or the CDN is unreachable. Caches the result for subsequent calls.

pub fn is_stale(&mut self) -> Result<bool>

Check if local cache is out of date compared to the CDN.

Returns true if there is no local cache or the CDN has a newer version. Returns false if up to date or if the CDN is unreachable.

pub fn ensure_parquet(&mut self, view_name: &str) -> Result<PathBuf>

Ensure a parquet file is cached locally, downloading if needed.

Arguments

• view_name - Logical view name (e.g. "cards", "sets").

Returns

Local filesystem path to the cached parquet file.

pub fn ensure_json(&mut self, name: &str) -> Result<PathBuf>

Ensure a JSON file is cached locally, downloading if needed.

Arguments

• name - Logical file name (e.g. "meta", "all_prices_today").

Returns

Local filesystem path to the cached JSON file.

pub fn load_json(&mut self, name: &str) -> Result<Value>

Load and parse a JSON file (handles .gz transparently).

If the cached file is corrupt (truncated download, disk error), it is deleted automatically so the next call re-downloads a fresh copy.

pub fn clear(&self) -> Result<()>

Remove all cached files and recreate the cache directory.

pub fn close(&mut self)

Close the HTTP client, if open.