GavinRay97
commented
2 years ago A note about the Javadoc on the class that mentions caching statements to results:
I tried to implement this but it turned out to be a bit trickier than I thought
Had started writing a class, EvaluationContext, which holds an Environment + Map<String, ForeignValue> + AstNode
So I thought that a Cache<EvaluationContext, CompiledStatement> could be implemented.
But the hashing doesn't seem to work, I always get cache misses =/
Implementing .equals() and .hashCode() on AstNode and MapEnvironment don't seem to change this 🤔
public class ProgrammaticShell implements Session.Shell {
// ...
private boolean enableCache = true;
private Cache<EvaluationContext, CompiledStatement> compiledStatementCache =
CacheBuilder.newBuilder().recordStats().build();
// ....
private void command(AstNode statement, Consumer<String> outLines) {
try {
final Map<String, Binding> outBindings = new LinkedHashMap<>();
final Environment env = env0.bindAll(outBindings.values());
final List<Binding> bindings = new ArrayList<>();
CompiledStatement compiled;
// If cache is enabled
if (enableCache) {
EvaluationContext context = new EvaluationContext(env0, foreignValueMap, statement);
CompiledStatement compiledStatement = compiledStatementCache.getIfPresent(context);
// If not in cache, compile and put in cache
if (compiledStatement == null) {
compiled = Compiles.prepareStatement(typeSystem, session, env,
statement, null, e -> appendToOutput(e, outLines));
compiledStatementCache.put(context, compiled);
} else {
// If in cache, use cached compiled statement
compiled = compiledStatement;
}
} else {
// If cache is disabled, compile and don't put in cache
compiled = Compiles.prepareStatement(typeSystem, session, env,
statement, null, e -> appendToOutput(e, outLines));
}
compiled.eval(session, env, outLines, bindings::add);
bindings.forEach(b -> outBindings.put(b.id.name, b));
} catch (Codes.MorelRuntimeException e) {
appendToOutput(e, outLines);
}
}
}final class EvaluationContext {
private final Session session;
private final Environment env;
private final Map<String, ForeignValue> foreignValueMap;
EvaluationContext(
Session session,
Environment env,
Map<String, ForeignValue> foreignValueMap) {
this.session = session;
this.env = env;
this.foreignValueMap = foreignValueMap;
}
public Session session() {
return session;
}
public Environment env() {
return env;
}
public Map<String, ForeignValue> foreignValueMap() {
return foreignValueMap;
}
@Override
public boolean equals(Object obj) {
if (obj == this) return true;
if (obj == null || obj.getClass() != this.getClass()) return false;
var that = (EvaluationContext) obj;
return Objects.equals(this.session, that.session) &&
Objects.equals(this.env, that.env) &&
Objects.equals(this.foreignValueMap, that.foreignValueMap);
}
@Override
public int hashCode() {
return Objects.hash(session, env, foreignValueMap);
}
@Override
public String toString() {
return "EvaluationContext[" +
"session=" + session + ", " +
"env=" + env + ", " +
"foreignValueMap=" + foreignValueMap + ']';
}
}
julianhyde
This is currently failing in the test, and I've tried to debug but unsure why (attempted to mirror the existing Shell code):EDIT: Removing
staticfrom the variable fixed it.