@NotNull
private static PsiExpression getTopLevel(Project project, @NotNull PsiExpression expression) {
int i = 0;
while (expression.getParent() instanceof PsiExpression) {
i++;
final PsiExpression parent = (PsiExpression) expression.getParent();
if (parent instanceof PsiConditionalExpression
&& ((PsiConditionalExpression) parent).getCondition() == expression) break;
expression = parent;
if (expression instanceof PsiAssignmentExpression) break;
if (i > 10 && expression instanceof PsiBinaryExpression) {
ParameterizedCachedValue<PsiExpression, Pair<Project, PsiExpression>> value =
expression.getUserData(TOP_LEVEL_EXPRESSION);
if (value != null && value.hasUpToDateValue()) {
return getToplevelExpression(
project, expression); // optimization: use caching for big hierarchies
}
}
}
return expression;
}
@Override
public CachedValueProvider.Result<PsiExpression> compute(
Pair<Project, PsiExpression> pair) {
PsiExpression param = pair.second;
Project project = pair.first;
PsiExpression topLevel = getTopLevel(project, param);
ParameterizedCachedValue<PsiExpression, Pair<Project, PsiExpression>> cachedValue =
param.getUserData(TOP_LEVEL_EXPRESSION);
assert cachedValue != null;
int i = 0;
for (PsiElement element = param;
element != topLevel;
element = element.getParent(), i++) {
if (i % 10
== 0) { // optimization: store up link to the top level expression in each 10nth
// element
element.putUserData(TOP_LEVEL_EXPRESSION, cachedValue);
}
}
return CachedValueProvider.Result.create(
topLevel, PsiManager.getInstance(project).getModificationTracker());
}