| // Copyright (C) 2012 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.gerrit.server.rules; |
| |
| import static com.google.common.base.Preconditions.checkState; |
| import static com.google.gerrit.server.project.ProjectCache.illegalState; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.base.CharMatcher; |
| import com.google.common.flogger.FluentLogger; |
| import com.google.gerrit.entities.Account; |
| import com.google.gerrit.entities.Change; |
| import com.google.gerrit.entities.LabelType; |
| import com.google.gerrit.entities.SubmitRecord; |
| import com.google.gerrit.entities.SubmitTypeRecord; |
| import com.google.gerrit.exceptions.StorageException; |
| import com.google.gerrit.extensions.client.SubmitType; |
| import com.google.gerrit.server.account.AccountCache; |
| import com.google.gerrit.server.account.Accounts; |
| import com.google.gerrit.server.account.Emails; |
| import com.google.gerrit.server.project.NoSuchProjectException; |
| import com.google.gerrit.server.project.ProjectCache; |
| import com.google.gerrit.server.project.ProjectState; |
| import com.google.gerrit.server.project.RuleEvalException; |
| import com.google.gerrit.server.query.change.ChangeData; |
| import com.google.inject.assistedinject.Assisted; |
| import com.google.inject.assistedinject.AssistedInject; |
| import com.googlecode.prolog_cafe.exceptions.CompileException; |
| import com.googlecode.prolog_cafe.exceptions.ReductionLimitException; |
| import com.googlecode.prolog_cafe.lang.IntegerTerm; |
| import com.googlecode.prolog_cafe.lang.ListTerm; |
| import com.googlecode.prolog_cafe.lang.Prolog; |
| import com.googlecode.prolog_cafe.lang.PrologMachineCopy; |
| import com.googlecode.prolog_cafe.lang.StructureTerm; |
| import com.googlecode.prolog_cafe.lang.SymbolTerm; |
| import com.googlecode.prolog_cafe.lang.Term; |
| import com.googlecode.prolog_cafe.lang.VariableTerm; |
| import java.io.StringReader; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| |
| /** |
| * Evaluates a submit-like Prolog rule found in the rules.pl file of the current project and filters |
| * the results through rules found in the parent projects, all the way up to All-Projects. |
| */ |
| public class PrologRuleEvaluator { |
| private static final FluentLogger logger = FluentLogger.forEnclosingClass(); |
| |
| private static final String DEFAULT_MSG = "Error evaluating project rules, check server log"; |
| |
| /** |
| * List of characters to allow in the label name, when an invalid name is used. Dash is allowed as |
| * it can't be the first character: we use a prefix. |
| */ |
| private static final CharMatcher VALID_LABEL_MATCHER = |
| CharMatcher.is('-') |
| .or(CharMatcher.inRange('a', 'z')) |
| .or(CharMatcher.inRange('A', 'Z')) |
| .or(CharMatcher.inRange('0', '9')); |
| |
| public interface Factory { |
| /** Returns a new {@link PrologRuleEvaluator} with the specified options */ |
| PrologRuleEvaluator create(ChangeData cd, PrologOptions options); |
| } |
| |
| /** |
| * Exception thrown when the label term of a submit record unexpectedly didn't contain a user |
| * term. |
| */ |
| private static class UserTermExpected extends Exception { |
| private static final long serialVersionUID = 1L; |
| |
| UserTermExpected(SubmitRecord.Label label) { |
| super(String.format("A label with the status %s must contain a user.", label.toString())); |
| } |
| } |
| |
| private final AccountCache accountCache; |
| private final Accounts accounts; |
| private final Emails emails; |
| private final RulesCache rulesCache; |
| private final PrologEnvironment.Factory envFactory; |
| private final ChangeData cd; |
| private final ProjectState projectState; |
| private final PrologOptions opts; |
| private Term submitRule; |
| |
| @AssistedInject |
| private PrologRuleEvaluator( |
| AccountCache accountCache, |
| Accounts accounts, |
| Emails emails, |
| RulesCache rulesCache, |
| PrologEnvironment.Factory envFactory, |
| ProjectCache projectCache, |
| @Assisted ChangeData cd, |
| @Assisted PrologOptions options) { |
| this.accountCache = accountCache; |
| this.accounts = accounts; |
| this.emails = emails; |
| this.rulesCache = rulesCache; |
| this.envFactory = envFactory; |
| this.cd = cd; |
| this.opts = options; |
| |
| this.projectState = projectCache.get(cd.project()).orElseThrow(illegalState(cd.project())); |
| } |
| |
| private static Term toListTerm(List<Term> terms) { |
| Term list = Prolog.Nil; |
| for (int i = terms.size() - 1; i >= 0; i--) { |
| list = new ListTerm(terms.get(i), list); |
| } |
| return list; |
| } |
| |
| private static boolean isUser(Term who) { |
| return who instanceof StructureTerm |
| && who.arity() == 1 |
| && who.name().equals("user") |
| && who.arg(0) instanceof IntegerTerm; |
| } |
| |
| private Term getSubmitRule() { |
| return submitRule; |
| } |
| |
| /** |
| * Evaluate the submit rules. |
| * |
| * @return {@link SubmitRecord} returned from the evaluated rules. Can include errors. |
| */ |
| public SubmitRecord evaluate() { |
| Change change; |
| try { |
| change = cd.change(); |
| if (change == null) { |
| throw new StorageException("No change found"); |
| } |
| |
| if (projectState == null) { |
| throw new NoSuchProjectException(cd.project()); |
| } |
| } catch (StorageException | NoSuchProjectException e) { |
| return ruleError("Error looking up change " + cd.getId(), e); |
| } |
| |
| List<Term> results; |
| try { |
| results = |
| evaluateImpl( |
| "locate_submit_rule", "can_submit", "locate_submit_filter", "filter_submit_results"); |
| } catch (RuleEvalException e) { |
| return ruleError(e.getMessage(), e); |
| } |
| |
| if (results.isEmpty()) { |
| // This should never occur. A well written submit rule will always produce |
| // at least one result informing the caller of the labels that are |
| // required for this change to be submittable. Each label will indicate |
| // whether or not that is actually possible given the permissions. |
| return ruleError( |
| String.format( |
| "Submit rule '%s' for change %s of %s has no solution.", |
| getSubmitRuleName(), cd.getId(), projectState.getName())); |
| } |
| |
| return resultsToSubmitRecord(getSubmitRule(), results); |
| } |
| |
| private String getSubmitRuleName() { |
| return submitRule == null ? "<unknown>" : submitRule.name(); |
| } |
| |
| /** |
| * Convert the results from Prolog Cafe's format to Gerrit's common format. |
| * |
| * <p>can_submit/1 terminates when an ok(P) record is found. Therefore walk the results backwards, |
| * using only that ok(P) record if it exists. This skips partial results that occur early in the |
| * output. Later after the loop the out collection is reversed to restore it to the original |
| * ordering. |
| */ |
| public SubmitRecord resultsToSubmitRecord(Term submitRule, List<Term> results) { |
| checkState(!results.isEmpty(), "the list of Prolog terms must not be empty"); |
| |
| SubmitRecord resultSubmitRecord = new SubmitRecord(); |
| resultSubmitRecord.labels = new ArrayList<>(); |
| for (int resultIdx = results.size() - 1; 0 <= resultIdx; resultIdx--) { |
| Term submitRecord = results.get(resultIdx); |
| |
| if (!(submitRecord instanceof StructureTerm) || 1 != submitRecord.arity()) { |
| return invalidResult(submitRule, submitRecord); |
| } |
| |
| if (!"ok".equals(submitRecord.name()) && !"not_ready".equals(submitRecord.name())) { |
| return invalidResult(submitRule, submitRecord); |
| } |
| |
| // This transformation is required to adapt Prolog's behavior to the way Gerrit handles |
| // SubmitRecords, as defined in the SubmitRecord#allRecordsOK method. |
| // When several rules are defined in Prolog, they are all matched to a SubmitRecord. We want |
| // the change to be submittable when at least one result is OK. |
| if ("ok".equals(submitRecord.name())) { |
| resultSubmitRecord.status = SubmitRecord.Status.OK; |
| } else if ("not_ready".equals(submitRecord.name()) && resultSubmitRecord.status == null) { |
| resultSubmitRecord.status = SubmitRecord.Status.NOT_READY; |
| } |
| |
| // Unpack the one argument. This should also be a structure with one |
| // argument per label that needs to be reported on to the caller. |
| // |
| submitRecord = submitRecord.arg(0); |
| |
| if (!(submitRecord instanceof StructureTerm)) { |
| return invalidResult(submitRule, submitRecord); |
| } |
| |
| for (Term state : ((StructureTerm) submitRecord).args()) { |
| if (!(state instanceof StructureTerm) |
| || 2 != state.arity() |
| || !"label".equals(state.name())) { |
| return invalidResult(submitRule, submitRecord); |
| } |
| |
| SubmitRecord.Label lbl = new SubmitRecord.Label(); |
| resultSubmitRecord.labels.add(lbl); |
| |
| lbl.label = checkLabelName(state.arg(0).name()); |
| Term status = state.arg(1); |
| |
| try { |
| if ("ok".equals(status.name())) { |
| lbl.status = SubmitRecord.Label.Status.OK; |
| appliedBy(lbl, status); |
| |
| } else if ("reject".equals(status.name())) { |
| lbl.status = SubmitRecord.Label.Status.REJECT; |
| appliedBy(lbl, status); |
| |
| } else if ("need".equals(status.name())) { |
| lbl.status = SubmitRecord.Label.Status.NEED; |
| |
| } else if ("may".equals(status.name())) { |
| lbl.status = SubmitRecord.Label.Status.MAY; |
| |
| } else if ("impossible".equals(status.name())) { |
| lbl.status = SubmitRecord.Label.Status.IMPOSSIBLE; |
| |
| } else { |
| return invalidResult(submitRule, submitRecord); |
| } |
| } catch (UserTermExpected e) { |
| return invalidResult(submitRule, submitRecord, e.getMessage()); |
| } |
| } |
| |
| if (resultSubmitRecord.status == SubmitRecord.Status.OK) { |
| break; |
| } |
| } |
| Collections.reverse(resultSubmitRecord.labels); |
| return resultSubmitRecord; |
| } |
| |
| @VisibleForTesting |
| static String checkLabelName(String name) { |
| try { |
| return LabelType.checkName(name); |
| } catch (IllegalArgumentException e) { |
| String newName = "Invalid-Prolog-Rules-Label-Name-" + sanitizeLabelName(name); |
| return LabelType.checkName(newName.replace("--", "-")); |
| } |
| } |
| |
| private static String sanitizeLabelName(String name) { |
| return VALID_LABEL_MATCHER.retainFrom(name); |
| } |
| |
| private static SubmitRecord createRuleError(String err) { |
| SubmitRecord rec = new SubmitRecord(); |
| rec.status = SubmitRecord.Status.RULE_ERROR; |
| rec.errorMessage = err; |
| return rec; |
| } |
| |
| private SubmitRecord invalidResult(Term rule, Term record, String reason) { |
| return ruleError( |
| String.format( |
| "Submit rule %s for change %s of %s output invalid result: %s%s", |
| rule, |
| cd.getId(), |
| cd.project().get(), |
| record, |
| (reason == null ? "" : ". Reason: " + reason))); |
| } |
| |
| private SubmitRecord invalidResult(Term rule, Term record) { |
| return invalidResult(rule, record, null); |
| } |
| |
| private SubmitRecord ruleError(String err) { |
| return ruleError(err, null); |
| } |
| |
| private SubmitRecord ruleError(String err, Exception e) { |
| if (opts.logErrors()) { |
| logger.atSevere().withCause(e).log(err); |
| return createRuleError(DEFAULT_MSG); |
| } |
| return createRuleError(err); |
| } |
| |
| /** |
| * Evaluate the submit type rules to get the submit type. |
| * |
| * @return record from the evaluated rules. |
| */ |
| public SubmitTypeRecord getSubmitType() { |
| try { |
| if (projectState == null) { |
| throw new NoSuchProjectException(cd.project()); |
| } |
| } catch (NoSuchProjectException e) { |
| return typeError("Error looking up change " + cd.getId(), e); |
| } |
| |
| List<Term> results; |
| try { |
| results = |
| evaluateImpl( |
| "locate_submit_type", |
| "get_submit_type", |
| "locate_submit_type_filter", |
| "filter_submit_type_results"); |
| } catch (RuleEvalException e) { |
| return typeError(e.getMessage(), e); |
| } |
| |
| if (results.isEmpty()) { |
| // Should never occur for a well written rule |
| return typeError( |
| "Submit rule '" |
| + getSubmitRuleName() |
| + "' for change " |
| + cd.getId() |
| + " of " |
| + projectState.getName() |
| + " has no solution."); |
| } |
| |
| Term typeTerm = results.get(0); |
| if (!(typeTerm instanceof SymbolTerm)) { |
| return typeError( |
| "Submit rule '" |
| + getSubmitRuleName() |
| + "' for change " |
| + cd.getId() |
| + " of " |
| + projectState.getName() |
| + " did not return a symbol."); |
| } |
| |
| String typeName = typeTerm.name(); |
| try { |
| return SubmitTypeRecord.OK(SubmitType.valueOf(typeName.toUpperCase())); |
| } catch (IllegalArgumentException e) { |
| return typeError( |
| "Submit type rule " |
| + getSubmitRule() |
| + " for change " |
| + cd.getId() |
| + " of " |
| + projectState.getName() |
| + " output invalid result: " |
| + typeName); |
| } |
| } |
| |
| private SubmitTypeRecord typeError(String err) { |
| return typeError(err, null); |
| } |
| |
| private SubmitTypeRecord typeError(String err, Exception e) { |
| if (opts.logErrors()) { |
| logger.atSevere().withCause(e).log(err); |
| return typeError(DEFAULT_MSG); |
| } |
| return SubmitTypeRecord.error(err); |
| } |
| |
| private List<Term> evaluateImpl( |
| String userRuleLocatorName, |
| String userRuleWrapperName, |
| String filterRuleLocatorName, |
| String filterRuleWrapperName) |
| throws RuleEvalException { |
| PrologEnvironment env = getPrologEnvironment(); |
| try { |
| Term sr = env.once("gerrit", userRuleLocatorName, new VariableTerm()); |
| List<Term> results = new ArrayList<>(); |
| try { |
| for (Term[] template : env.all("gerrit", userRuleWrapperName, sr, new VariableTerm())) { |
| results.add(template[1]); |
| } |
| } catch (ReductionLimitException err) { |
| throw new RuleEvalException( |
| String.format( |
| "%s on change %d of %s", |
| err.getMessage(), cd.getId().get(), projectState.getName())); |
| } catch (RuntimeException err) { |
| throw new RuleEvalException( |
| String.format( |
| "Exception calling %s on change %d of %s", |
| sr, cd.getId().get(), projectState.getName()), |
| err); |
| } |
| |
| Term resultsTerm = toListTerm(results); |
| if (!opts.skipFilters()) { |
| resultsTerm = |
| runSubmitFilters(resultsTerm, env, filterRuleLocatorName, filterRuleWrapperName); |
| } |
| List<Term> r; |
| if (resultsTerm instanceof ListTerm) { |
| r = new ArrayList<>(); |
| for (Term t = resultsTerm; t instanceof ListTerm; ) { |
| ListTerm l = (ListTerm) t; |
| r.add(l.car().dereference()); |
| t = l.cdr().dereference(); |
| } |
| } else { |
| r = Collections.emptyList(); |
| } |
| submitRule = sr; |
| return r; |
| } finally { |
| env.close(); |
| } |
| } |
| |
| private PrologEnvironment getPrologEnvironment() throws RuleEvalException { |
| PrologEnvironment env; |
| try { |
| PrologMachineCopy pmc; |
| if (opts.rule().isPresent()) { |
| pmc = rulesCache.loadMachine("stdin", new StringReader(opts.rule().get())); |
| } else { |
| pmc = |
| rulesCache.loadMachine( |
| projectState.getNameKey(), projectState.getConfig().getRulesId().orElse(null)); |
| } |
| env = envFactory.create(pmc); |
| } catch (CompileException err) { |
| String msg; |
| if (opts.rule().isPresent()) { |
| msg = err.getMessage(); |
| } else { |
| msg = |
| String.format( |
| "Cannot load rules.pl for %s: %s", projectState.getName(), err.getMessage()); |
| } |
| throw new RuleEvalException(msg, err); |
| } |
| env.set(StoredValues.ACCOUNTS, accounts); |
| env.set(StoredValues.ACCOUNT_CACHE, accountCache); |
| env.set(StoredValues.EMAILS, emails); |
| env.set(StoredValues.CHANGE_DATA, cd); |
| env.set(StoredValues.PROJECT_STATE, projectState); |
| return env; |
| } |
| |
| private Term runSubmitFilters( |
| Term results, |
| PrologEnvironment env, |
| String filterRuleLocatorName, |
| String filterRuleWrapperName) |
| throws RuleEvalException { |
| PrologEnvironment childEnv = env; |
| ChangeData cd = env.get(StoredValues.CHANGE_DATA); |
| ProjectState projectState = env.get(StoredValues.PROJECT_STATE); |
| for (ProjectState parentState : projectState.parents()) { |
| PrologEnvironment parentEnv; |
| try { |
| parentEnv = |
| envFactory.create( |
| rulesCache.loadMachine( |
| parentState.getNameKey(), parentState.getConfig().getRulesId().orElse(null))); |
| } catch (CompileException err) { |
| throw new RuleEvalException("Cannot consult rules.pl for " + parentState.getName(), err); |
| } |
| |
| parentEnv.copyStoredValues(childEnv); |
| Term filterRule = parentEnv.once("gerrit", filterRuleLocatorName, new VariableTerm()); |
| try { |
| Term[] template = |
| parentEnv.once( |
| "gerrit", filterRuleWrapperName, filterRule, results, new VariableTerm()); |
| results = template[2]; |
| } catch (ReductionLimitException err) { |
| throw new RuleEvalException( |
| String.format( |
| "%s on change %d of %s", |
| err.getMessage(), cd.getId().get(), parentState.getName())); |
| } catch (RuntimeException err) { |
| throw new RuleEvalException( |
| String.format( |
| "Exception calling %s on change %d of %s", |
| filterRule, cd.getId().get(), parentState.getName()), |
| err); |
| } |
| childEnv = parentEnv; |
| } |
| return results; |
| } |
| |
| private void appliedBy(SubmitRecord.Label label, Term status) throws UserTermExpected { |
| if (status instanceof StructureTerm && status.arity() == 1) { |
| Term who = status.arg(0); |
| if (isUser(who)) { |
| label.appliedBy = Account.id(((IntegerTerm) who.arg(0)).intValue()); |
| } else { |
| throw new UserTermExpected(label); |
| } |
| } |
| } |
| } |
