From 295416dd2dc52285b57506811512cb442e7d49f2 Mon Sep 17 00:00:00 2001
From: Jacob Quinn <quinn.jacobd@gmail.com>
Date: Sat, 3 Apr 2021 21:24:10 -0600
Subject: [PATCH] Don't store table metadata globally (#165)

* Don't store table metadata globally

Fixes #90. There's no need to store table metadata globally when we can
just store it in the Table type itself and overload the `getmetadata`.
This should avoid metadata bloat in the global store.
---
 src/table.jl | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/table.jl b/src/table.jl
index f4e89ef1..e4dd2be2 100644
--- a/src/table.jl
+++ b/src/table.jl
@@ -159,15 +159,18 @@ struct Table <: Tables.AbstractColumns
     columns::Vector{AbstractVector}
     lookup::Dict{Symbol, AbstractVector}
     schema::Ref{Meta.Schema}
+    metadata::Ref{Dict{String, String}}
 end
 
-Table() = Table(Symbol[], Type[], AbstractVector[], Dict{Symbol, AbstractVector}(), Ref{Meta.Schema}())
+Table() = Table(Symbol[], Type[], AbstractVector[], Dict{Symbol, AbstractVector}(), Ref{Meta.Schema}(), Ref{Dict{String, String}}())
+Table(names, types, columns, lookup, schema) = Table(names, types, columns, lookup, schema, Ref{Dict{String, String}}())
 
 names(t::Table) = getfield(t, :names)
 types(t::Table) = getfield(t, :types)
 columns(t::Table) = getfield(t, :columns)
 lookup(t::Table) = getfield(t, :lookup)
 schema(t::Table) = getfield(t, :schema)
+getmetadata(t::Table) = isdefined(getfield(t, :metadata), :x) ? getfield(t, :metadata)[] : nothing
 
 Tables.istable(::Table) = true
 Tables.columnaccess(::Table) = true
@@ -272,7 +275,7 @@ function Table(bytes::Vector{UInt8}, off::Integer=1, tlen::Union{Integer, Nothin
     end
     meta = sch !== nothing ? sch.custom_metadata : nothing
     if meta !== nothing
-        setmetadata!(t, Dict(String(kv.key) => String(kv.value) for kv in meta))
+        getfield(t, :metadata)[] = Dict(x.key=>x.value for x in meta)
     end
     return t
 end