in src/write.jl [612:647]
function makeschema(b, sch::Tables.Schema, columns)
names = sch.names
N = length(names)
fieldoffsets = [fieldoffset(b, names[i], columns.cols[i]) for i = 1:N]
Meta.schemaStartFieldsVector(b, N)
for off in Iterators.reverse(fieldoffsets)
FlatBuffers.prependoffset!(b, off)
end
fields = FlatBuffers.endvector!(b, N)
if columns.metadata !== nothing
kvs = columns.metadata
kvoffs = Vector{FlatBuffers.UOffsetT}(undef, length(kvs))
for (i, (k, v)) in enumerate(kvs)
koff = FlatBuffers.createstring!(b, String(k))
voff = FlatBuffers.createstring!(b, String(v))
Meta.keyValueStart(b)
Meta.keyValueAddKey(b, koff)
Meta.keyValueAddValue(b, voff)
kvoffs[i] = Meta.keyValueEnd(b)
end
Meta.schemaStartCustomMetadataVector(b, length(kvs))
for off in Iterators.reverse(kvoffs)
FlatBuffers.prependoffset!(b, off)
end
meta = FlatBuffers.endvector!(b, length(kvs))
else
meta = FlatBuffers.UOffsetT(0)
end
Meta.schemaStart(b)
Meta.schemaAddEndianness(b, Meta.Endianness.Little)
Meta.schemaAddFields(b, fields)
Meta.schemaAddCustomMetadata(b, meta)
return Meta.schemaEnd(b)
end