feat: Add Apache AGE graph database extension

[jpabbuehl]

Summary

Add support for Apache AGE (A Graph Extension) which brings graph database capabilities and Cypher query language to PGlite.

Changes

Build Configuration

File	Change
pglite/Makefile	Add age to SUBDIRS, add age-specific build rule with SIZEOF_DATUM=4
pglite-wasm/included.pglite.imports	Export hook symbols for AGE
pglite-wasm/excluded.pglite.imports	Add invoke_jii pattern

AGE Submodule

Added AGE as a submodule from jpabbuehl/age branch feat/32bit-wasm-support.

This fork uses a Makefile-only approach for 32-bit WASM compatibility:

• No changes to graphid.h or age_main.sql source files
• Makefile conditionally strips PASSEDBYVALUE from graphid type when SIZEOF_DATUM=4 is passed

Upstream PR pending: apache/age@master...jpabbuehl:age:feat/32bit-wasm-support

Symbol Exports

AGE requires these PostgreSQL hook symbols:

• post_parse_analyze_hook — Cypher query parsing
• set_rel_pathlist_hook — Query planning
• ProcessUtility_hook — DDL handling
• RegisterExtensibleNodeMethods — Custom node types
• object_access_hook — Access control

Also added invoke_jii to excluded imports (AGE uses int64(*)(int,int) function pointer pattern).

Technical Details

32-bit WASM Compatibility

PGlite compiles with -m32 (32-bit WASM). AGE's graphid type is 8 bytes, which doesn't fit in a 32-bit Datum.

Build-time solution (Makefile-only):

In pglite/Makefile - passes SIZEOF_DATUM=4 to AGE build:

age.tar.gz:
    rm -f age/age--*.sql  # Force SQL regeneration
    $(MAKE) -C age install SIZEOF_DATUM=4

In AGE's Makefile - strips PASSEDBYVALUE when SIZEOF_DATUM=4:

$(age_sql): $(SQLS)
    @cat $(SQLS) > $@
ifeq ($(SIZEOF_DATUM),4)
    @sed 's/^  PASSEDBYVALUE,$$/  -- PASSEDBYVALUE removed for 32-bit/' $@ > [email protected] && mv [email protected] $@
endif

This approach:

• Keeps AGE source files unchanged from upstream
• Relies on PostgreSQL's existing Int64GetDatum/DatumGetInt64 macros (already handle 32-bit pass-by-reference)
• Only modifies the generated SQL at build time

Testing

• AGE compiles to WASM successfully
• age.tar.gz generated (140KB compressed)
• All 34 TypeScript tests pass

Related PRs

• pglite TypeScript wrapper: electric-sql/pglite@main...jpabbuehl:pglite:feat/age-extension
• AGE 32-bit compatibility (upstream): apache/age@master...jpabbuehl:age:feat/32bit-wasm-support

Checklist

• Build succeeds with ./build-with-docker.sh
• AGE extension tarball generated
• No regressions in existing extensions