Struct HashIndex 

pub struct HashIndex {
    pub file_count: usize,
    pub total_symbols: usize,
    /* private fields */
}

Index of file hashes for incremental indexing.

This structure maintains a mapping from file paths to their hash information, enabling fast change detection during re-indexing operations.

Fields

file_count: usize

Total number of files tracked

total_symbols: usize

Total number of symbols across all files

Implementations

impl HashIndex

pub fn new() -> Self

Create a new empty hash index.

pub fn with_content_cache_limit(limit: Option<usize>) -> Self

Create a new hash index with an explicit content cache limit.

pub fn set_content_cache_limit(&mut self, limit: Option<usize>)

Override the content cache limit at runtime.

pub fn has_changed(&self, path: &Path) -> Result<bool>

Check if a file has changed using 3-level detection.

Returns true if the file should be re-indexed, false if it can be skipped.

Detection Levels

1. Existence: If file not in index or doesn’t exist on disk → changed
2. Metadata: If size or mtime differs → check hash
3. Hash: If hash differs → changed

Errors

Returns an error if file metadata cannot be read or file cannot be hashed.

pub fn update(&mut self, path: PathBuf, file_hash: FileHash)

Update the hash index with new file information.

This should be called after successfully indexing a file.

pub fn remove(&mut self, path: &Path) -> Option<FileHash>

Remove a file from the index.

This should be called when a file is deleted from the codebase.

pub fn get(&self, path: &Path) -> Option<&FileHash>

Get hash information for a file.

pub fn iter(&self) -> impl Iterator<Item = (&PathBuf, &FileHash)>

Iterate over all tracked files.

pub fn len(&self) -> usize

Get the number of tracked files.

pub fn is_empty(&self) -> bool

Check if the index is empty.

pub fn clear(&mut self)

Clear all entries from the index.

pub fn get_cached_content(&self, path: &Path) -> Result<String>

Get cached content for a file (Phase 3).

Returns the cached content if available in memory. This method is used by content-based diffing to obtain old file content for comparison with the current file state.

Errors

Returns an error if the content is not cached (was never cached or file too large). This is intentional - we ONLY want cached content, not current disk content.

pub fn cache_content(&mut self, path: &Path, content: String)

Cache file content for a file (Phase 3).

Stores file content in memory for fast content-based diffing. The maximum cached size is controlled by content_cache_max_bytes; when set to None the cache is unbounded.

This is called after successfully parsing a file to enable fast incremental updates on the next change.

Size Limit

Files larger than 100KB are not cached. This threshold can be tuned based on memory constraints and typical file sizes in the codebase.

pub fn save(&self, cache_dir: &Path) -> Result<()>

Save the hash index to disk.

The index is saved to {cache_dir}/file_hashes.bin using a versioned envelope with postcard serialization (atomic write).

Errors

Returns an error if the cache directory cannot be created or the file cannot be written.

pub fn load(cache_dir: &Path) -> Result<Self>

Load the hash index from disk.

If the file doesn’t exist or cannot be read, returns an empty index.

Errors

Returns an error only if the file exists but cannot be deserialized (indicating corruption).

Trait Implementations

impl Clone for HashIndex

fn clone(&self) -> HashIndex

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HashIndex

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

Formats the value using the given formatter.

impl Default for HashIndex

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for HashIndex

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for HashIndex

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.