maxminddb-golang

This is the first beta of the v2 releases. Go 1.23 is required. I don't expect to do a final release until Go 1.24 is available. See #141 for the v2 roadmap.

Notable changes:

• (*Reader).Lookup now takes only the IP address and returns a Result. Lookup(ip, &rec) would now become Lookup(ip).Decode(&rec).
• (*Reader).LookupNetwork has been removed. To get the network for a result, use (Result).Prefix().
• (*Reader).LookupOffset now takes an offset and returns a Result. Result has an Offset() method that returns the offset value. (*Reader).Decode has been removed.
• Use of net.IP and *net.IPNet have been replaced with netip.Addr and netip.Prefix.
• You may now decode a particular path within a database record using (Result).DecodePath. For instance, to decode just the country code in GeoLite2 Country to a string called code, you might do something like Lookup(ip).DecodePath(&code, "country", "iso_code"). Strings should be used for map keys and ints for array indexes.
• (*Reader).Networks and (*Reader).NetworksWithin now return a Go 1.23 iterator of Result values. Aliased networks are now skipped by default. If you wish to include them, use the IncludeAliasedNetworks option.

• Return the *net.IPNet in canonical form when using NetworksWithin to look up a network more specific than the one in the database. Previously, the IP field on the *net.IPNet would be set to the IP from the lookup network rather than the first IP of the network.
• NetworksWithin will now correctly handle an *net.IPNet parameter that is not in canonical form. This issue would only occur if the *net.IPNet was manually constructed, as net.ParseCIDR returns the value in canonical form even if the input string is not.

• Go 1.21 or greater is now required.
• The error messages when decoding have been improved. #119

• The wasi target is now built without memory-mapping support. Pull request
  by Alex Kashintsev. GitHub #114.
• When decoding to a map of non-scalar, non-interface types such as a
  map[string]map[string]any, the decoder failed to zero out the value for
  the map elements, which could result in incorrect decoding. Reported by
  JT Olio. GitHub #115.

• wasm and wasip1 targets are now built without memory-mapping support.
  Pull request by Randy Reddig. GitHub #110.

Full Changelog: https://github.com/oschwald/maxminddb-golang/compare/v1.10.0...v1.11.0

• Set Go version in go.mod file to 1.18.

• Set the minimum Go version in the go.mod file to 1.17.
• Updated dependencies.
• Minor performance improvements to the custom deserializer feature
  added in 1.8.0.

• Added maxminddb.SkipAliasedNetworks option to Networks and
  NetworksWithin methods. When set, this option will cause the
  iterator to skip networks that are aliases of the IPv4 tree.
• Added experimental custom deserializer support. This allows
  much more control over the deserialization. The API is
  subject to change and you should use at your own risk.

• Add NetworksWithin method. This returns an iterator that traverses all networks in the database that are contained in the given network. Pull request by Olaf Alders. GitHub #65.

• This module now uses Go modules. Requested by Matthew Rothenberg.
  GitHub #49.
• Plan 9 is now supported. Pull request by Jacob Moody. GitHub #61.
• Documentation fixes. Pull request by Olaf Alders. GitHub #62.
• Thread-safety is now mentioned in the documentation. Requested by
  Ken Sedgwick. GitHub #39.
• Fix off-by-one error in file offset safety check. Reported by Will
  Storey. GitHub #63.

• Drop support for Go 1.7 and 1.8.
• Minor performance improvements.

• Add the method LookupNetwork. This returns the network that the
  record belongs to as well as a boolean indicating whether there was a
  record for the IP address in the database. GitHub #59.
• Improve performance.

• Fix issue with the finalizer running too early on Go 1.12 when using
  the Verify method. Reported by Robert-André Mauchin. GitHub #55.
• Remove unnecessary call to reflect.ValueOf. PR by SenseyeDeveloper.
  GitHub #53.

• The methods on the maxminddb.Reader struct now return an error if
  called on a closed database reader. Previously, this could cause a
  segmentation violation when using a memory-mapped file.
• The Close method on the maxminddb.Reader struct now sets the
  underlying buffer to nil, even when using FromBytes or Open on
  Google App Engine.
• No longer uses constants from syscall

• Fix incorrect index being used when decoding into anonymous struct fields. PR #42 by Andy Bursavich.

• The database decoder now does bound checking when decoding data from the database. This is to help ensure that the reader does not panic when given a corrupt database to decode. Closes #37.
• The reader will now return an error on a data structure with a depth greater than 512. This is done to prevent the possibility of a stack overflow on a cyclic data structure in a corrupt database. This matches the maximum depth allowed by libmaxminddb. All MaxMind databases currently have a depth of less than five.

• Added appengine build tag for Windows. When enabled, memory-mapping will be
  disabled in the Windows build as it is for the non-Windows build. Pull
  request #35 by Ingo Oeser.
• SetFinalizer is now used to unmap files if the user fails to close the
  reader. Using r.Close() is still recommended for most use cases.
• Previously, an unsafe conversion between []byte and string was used to
  avoid unnecessary allocations when decoding struct keys. The decoder now
  relies on a compiler optimization on string([]byte) map lookups to achieve
  this rather than using unsafe.

New release for those using tagged releases.