v0.2.0

Term additions no longer copy into the C heap

AddTerm is the one call an indexer makes per token, and C.CString made each one cost three crossings into C — malloc, the call, free — where one is needed. The shim now takes a pointer and a length, and the Go side hands over the string's own bytes.

Measured against a real Xapian database (512 terms per document, Go 1.26, xapian-core 2.0.0):

	ns/term
before	254.8
after	201.8
	−21%

The 53 ns saved matches a standalone measurement of the allocation pair to within 3%. Of what remains, roughly 185 ns is Xapian indexing the term and 16.5 ns is the crossing — so this is most of what a binding can remove without changing the API.

Terms are bytes, on both sides

QueryTerm takes the same shape, and not for speed. Converting only the write path meant a term containing a NUL was indexed whole and then never found, because the query truncated it. Both paths now agree on what a term is.

Safety

Xapian's add_term takes const std::string & and stores a copy; the pointer is not retained past the call, which is what makes passing Go memory legal here. TestTermsSurviveTheStringsTheyCameFrom asserts the consequence rather than the claim — source strings are dropped and the heap churned before the terms are read back, because a retained pointer would return garbage rather than fail. Tests pass under GOEXPERIMENT=cgocheck2 and -race.

Breaking, at the C level only

fcx_doc_add_term, fcx_doc_add_boolean_term and fcx_query_term now take an explicit length. The Go API is unchanged — no caller of this module needs edits beyond the version bump.

Full diff: v0.1.0...v0.2.0

v0.1.0

Initial release of go-xapian — a thin, dependency-free cgo binding over the Xapian C++ search library, extracted from the yarilo mail server for independent reuse.

Features

• WDB — writable database: open, commit, replace/delete document, set/get metadata, doc count/exists.
• DB — read database (combines shards): open-multi, last docid, docids, compact, search.
• Doc — document builder: add free-text / boolean terms.
• Query — wildcard / term / match-all / combine (AND, OR, AND_NOT).
• MSetEntry — ranked search hits (docid + weight).

Xapian C++ exceptions are converted into Go errors via an extern "C" shim.

Requirements

• Go 1.26+
• libxapian development headers (libxapian-dev / brew install xapian)

License

GPL-2.0-or-later (Xapian is GPL; linking it makes this binding GPL too).