Examples with FieldResolver io.crate.analyze.relations.FieldResolver used on opensource projects

Example 1 with FieldResolver

use of io.crate.analyze.relations.FieldResolver in project crate by crate.

the class Rename method rewriteToFetch.

@Nullable
@Override
public FetchRewrite rewriteToFetch(TableStats tableStats, Collection<Symbol> usedColumns) {
    IdentityHashMap<Symbol, Symbol> parentToChildMap = new IdentityHashMap<>(outputs.size());
    IdentityHashMap<Symbol, Symbol> childToParentMap = new IdentityHashMap<>(outputs.size());
    for (int i = 0; i < outputs.size(); i++) {
        parentToChildMap.put(outputs.get(i), source.outputs().get(i));
        childToParentMap.put(source.outputs().get(i), outputs.get(i));
    }
    ArrayList<Symbol> mappedUsedColumns = new ArrayList<>();
    for (Symbol usedColumn : usedColumns) {
        SymbolVisitors.intersection(usedColumn, outputs, s -> {
            Symbol childSymbol = parentToChildMap.get(s);
            assert childSymbol != null : "There must be a mapping available for symbol " + s;
            mappedUsedColumns.add(childSymbol);
        });
    }
    FetchRewrite fetchRewrite = source.rewriteToFetch(tableStats, mappedUsedColumns);
    if (fetchRewrite == null) {
        return null;
    }
    LogicalPlan newSource = fetchRewrite.newPlan();
    ArrayList<Symbol> newOutputs = new ArrayList<>();
    for (Symbol output : newSource.outputs()) {
        if (output instanceof FetchMarker) {
            FetchMarker marker = (FetchMarker) output;
            FetchMarker newMarker = new FetchMarker(name, marker.fetchRefs(), marker.fetchId());
            newOutputs.add(newMarker);
            childToParentMap.put(marker, newMarker);
        } else {
            Symbol mappedOutput = requireNonNull(childToParentMap.get(output), () -> "Mapping must exist for output from source. `" + output + "` is missing in " + childToParentMap);
            newOutputs.add(mappedOutput);
        }
    }
    LinkedHashMap<Symbol, Symbol> replacedOutputs = new LinkedHashMap<>();
    Function<Symbol, Symbol> convertChildrenToScopedSymbols = s -> MapBackedSymbolReplacer.convert(s, childToParentMap);
    for (var entry : fetchRewrite.replacedOutputs().entrySet()) {
        Symbol key = entry.getKey();
        Symbol value = entry.getValue();
        Symbol parentSymbolForKey = requireNonNull(childToParentMap.get(key), () -> "Mapping must exist for output from source. `" + key + "` is missing in " + childToParentMap);
        replacedOutputs.put(parentSymbolForKey, convertChildrenToScopedSymbols.apply(value));
    }
    Rename newRename = new Rename(newOutputs, name, fieldResolver, newSource);
    return new FetchRewrite(replacedOutputs, newRename);
}