Struct MmdbReader 

pub struct MmdbReader { /* private fields */ }

Available on crate feature net only.

A zero-copy reader over a MaxMind DB.

The database buffer is shared, so cloning a reader is cheap and a single database can be queried concurrently from many tasks without locks. The bytes are either held in memory (Self::from_bytes / Self::open) or, with the mmap feature, memory-mapped from disk via open_mmap.

Implementations

impl MmdbReader

pub fn from_bytes(bytes: impl Into<Bytes>) -> Result<MmdbReader, GeoIpError>

Build a reader from raw database bytes already held in memory.

Errors

Returns GeoIpError if the bytes are not a valid MaxMind DB or use an unsupported record size / format version.

pub fn open(path: impl AsRef<Path>) -> Result<MmdbReader, GeoIpError>

Read a MaxMind DB from disk into memory.

The whole file is read into a shared buffer. With the mmap feature, open_mmap maps the file instead for a smaller resident set on very large databases.

Errors

Returns GeoIpError::Io if the file cannot be read, or another GeoIpError if it is not a valid database.

pub fn open_mmap(path: impl AsRef<Path>) -> Result<MmdbReader, GeoIpError>

Available on crate feature mmap only.

Memory-map a MaxMind DB from disk instead of reading it into memory.

Lookups fault in only the pages they touch, so a large database costs little resident memory. The mapping is held for the reader’s lifetime.

The file must not be modified or truncated while the reader is alive, or lookups may observe garbage (or fault on some platforms).

Errors

Returns GeoIpError::Io if the file cannot be opened or mapped, or another GeoIpError if it is not a valid database.

pub fn with_language(self, lang: impl Into<Box<str>>) -> MmdbReader

Set the preferred language code used to resolve localised names (default "en"). This is the lookup key into the database’s localised names maps (e.g. "en", "de", "pt-BR").

pub fn metadata(&self) -> &Metadata

The parsed Metadata of this database.

pub fn lookup(&self, ip: IpAddr) -> Option<GeoLocationRef<'_>>

Look up ip, returning a zero-copy view of its record if present.

IPv4-mapped IPv6 inputs are canonicalised to IPv4 first. Looking up an IPv4 address in an IPv6 database traverses the ::/96 range.

This is best-effort: a structurally corrupt database encountered mid lookup yields None, indistinguishable from a legitimate miss. Use Self::try_lookup when you need to observe corruption.

pub fn try_lookup( &self, ip: IpAddr, ) -> Result<Option<GeoLocationRef<'_>>, GeoIpError>

Like Self::lookup, but reports database corruption encountered during traversal as a GeoIpError instead of collapsing it to None.

Errors

Returns GeoIpError::Corrupt if the search tree is structurally invalid for ip.

Trait Implementations

impl Clone for MmdbReader

fn clone(&self) -> MmdbReader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MmdbReader

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

Formats the value using the given formatter.