Module ewkb 

EWKB (Extended Well-Known Binary) wire format encoder and decoder, used as the on-disk and over-the-wire representation for geometry BLOBs. EWKB (Extended Well-Known Binary) parser and writer.

Wire format: [0x01|0x00]: byte order marker (little-endian or big-endian) [u32]: geometry type with flags (in the declared byte order) Bit 29 (0x20000000): SRID present Bit 31 (0x80000000): Z dimension Bit 30 (0x40000000): M dimension Bits 0-28: geometry type (1=Point, 2=LineString, etc.) [i32]: SRID (only when SRID flag set, in declared byte order) [rest]: ISO WKB geometry payload

Structs

EwkbHeader

Parsed EWKB header metadata.

Constants

EWKB_M_FLAG

EWKB type flag: coordinates include an M (measure) dimension.

EWKB_SRID_FLAG

EWKB type flag: SRID is present immediately after the type word.

EWKB_Z_FLAG

EWKB type flag: coordinates include a Z dimension.

MAX_NESTING_DEPTH

Max container nesting the EWKB parsers accept. geozero’s recursive to_geo/to_wkt/to_json overflow the stack around depth ~1500 (lower on WASM), so a crafted ~9 KB blob aborts the process. Real geometries nest a handful of levels, so this never bites legitimate data.

WKB_GEOMETRYCOLLECTION

ISO WKB geometry type code: GeometryCollection.

WKB_LINESTRING

ISO WKB geometry type code: LineString.

WKB_MULTILINESTRING

ISO WKB geometry type code: MultiLineString.

WKB_MULTIPOINT

ISO WKB geometry type code: MultiPoint.

WKB_MULTIPOLYGON

ISO WKB geometry type code: MultiPolygon.

WKB_POINT

ISO WKB geometry type code: Point.

WKB_POLYGON

ISO WKB geometry type code: Polygon.

Functions

concat_multipolygon_bodies

Return a static string naming the variant of a geo::Geometry value (for diagnostics).

ensure_ewkb_nesting_ok

Reject EWKB whose nesting exceeds MAX_NESTING_DEPTH, guarding the recursive geozero decoders against stack overflow. Reads only structural counts, never the coordinate payload.

ensure_matching_srid

Enforce equal SRIDs for binary geometry operations.

ensure_xy_only

Reject Z/M coordinate layouts when the operation can only process XY.

extract_mbr

Compute the planar minimum bounding rectangle of an EWKB blob without allocating a Geometry enum.

extract_srid

Extract only the SRID from an EWKB blob (cheap, no geometry parsing).

geom_type_name

Return a human-readable geometry type name (PostGIS convention).

geometry_type_name

Return the human-readable name of a geo::Geometry enum variant.

is_empty_point_blob

Return true when the EWKB blob encodes POINT EMPTY.

parse_ewkb

Parse an EWKB blob into a geo::Geometry<f64>. Returns (geometry, srid).

parse_ewkb_header

Peek at the EWKB header without fully parsing the geometry.

parse_ewkb_pair

Parse two EWKB blobs and enforce matching SRID.

set_srid

Rewrite the SRID in an existing EWKB blob without re-parsing the geometry.

validate_ewkb_payload

Validate EWKB header + payload structure without forcing XY-only dimensions and without deserializing through geozero.

validate_xy_ewkb_payload

Validate EWKB header + payload and enforce XY-only coordinate dimensions.

write_ewkb

Serialise a geo::Geometry<f64> to EWKB with an optional SRID.