Struct PackedReader 

pub struct PackedReader { /* private fields */ }

Reader for a local packed dataset. Remote/HTTP reads are the TS reader’s job; this opens objects from the filesystem.

Mirrors ArchiveReader: entries returns the decoded v5 directory, metadata the folded metadata, and read_payload selects the entry’s pack, slices [offset..offset+length], verifies CRC32C and decompresses the per-blob zstd. Packs are mmap’d lazily by pack_id.

Implementations

impl PackedReader

pub fn open<P: AsRef<Path>>(manifest_path: P) -> Result<Self>

Open a packed dataset by its manifest.json path. The directory and pack objects are resolved relative to the manifest’s parent directory.

pub fn open_bundle<P: AsRef<Path>>(path: P) -> Result<Self>

Open a single-file .sttb bundle (spec §13, the interchange profile). The bundle is mmap’d once; the manifest comes verbatim from the header, each pack becomes an (offset, length) window into the mapping, and everything below read_payload is shared with the exploded-directory open path — including the manifest format/version/capability refusals.

pub fn entries(&self) -> &[TileEntry]

All directory entries (sorted by zoom then Hilbert index).

pub fn metadata(&self) -> &Metadata

Dataset metadata.

pub fn capabilities(&self) -> &[String]

The manifest’s capabilities declarations (spec §3.1). A tool that repacks this dataset’s tiles verbatim MUST carry these forward via PackWriter::with_capabilities — dropping them re-arms the silent-misdecode hazard the declaration exists to prevent.

pub fn read_payload(&self, entry: &TileEntry) -> Result<Vec<u8>>

Read and decompress a tile’s raw payload bytes, verifying its CRC32C.

Selects the pack by entry.pack_id, slices [offset..offset+length] within it, checks the CRC, then decompresses the per-blob zstd. Mirrors ArchiveReader::read_payload.

pub fn read_layers(&self, entry: &TileEntry) -> Result<Vec<DecodedLayer>>

Read and decode a tile into its Arrow layers.

pub fn decode_payload(&self, payload: &[u8]) -> Result<Vec<DecodedLayer>>

Decode a tile payload under this dataset’s declared formatVersion.

The manifest is authoritative (design §1 ★F6): a v2 frame inside a v1-declared dataset is a hard error, and vice versa — never a silent best-effort decode of a mixed-version dataset. v2 frames resolve their template references through the registry built at open.

pub fn format_version(&self) -> u32

The manifest’s authoritative formatVersion (1 | 2). A tool that repacks this dataset’s payloads verbatim MUST write the same version (PackWriter::with_format_version) — frames and manifest declarations may not mix.

pub fn templates(&self) -> Option<&TemplateRegistry>

The v2 schema-template registry decoded from manifest.schemas (None on v1 datasets). Exposed so tools that fetch payloads through read_payload can decode them out-of-band via crate::arrow_tile::decode_tile_with_templates.