com.google.gerrit.server.restapi.project.ListBranches Maven / Gradle / Ivy
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// Copyright (C) 2013 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.restapi.project;
import static com.google.gerrit.entities.RefNames.isConfigRef;
import com.google.auto.value.AutoValue;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ComparisonChain;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMultimap;
import com.google.common.collect.Sets;
import com.google.gerrit.entities.Project;
import com.google.gerrit.entities.RefNames;
import com.google.gerrit.extensions.api.projects.BranchInfo;
import com.google.gerrit.extensions.api.projects.ProjectApi.ListRefsRequest;
import com.google.gerrit.extensions.common.ActionInfo;
import com.google.gerrit.extensions.common.WebLinkInfo;
import com.google.gerrit.extensions.registration.DynamicMap;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.extensions.restapi.BadRequestException;
import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
import com.google.gerrit.extensions.restapi.Response;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.extensions.restapi.RestReadView;
import com.google.gerrit.extensions.restapi.RestView;
import com.google.gerrit.extensions.webui.UiAction;
import com.google.gerrit.proto.Entities.PaginationToken;
import com.google.gerrit.proto.Protos;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.WebLinks;
import com.google.gerrit.server.extensions.webui.UiActions;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.gerrit.server.permissions.PermissionBackend;
import com.google.gerrit.server.permissions.PermissionBackendException;
import com.google.gerrit.server.permissions.RefPermission;
import com.google.gerrit.server.project.BranchResource;
import com.google.gerrit.server.project.ProjectResource;
import com.google.gerrit.server.project.ProjectState;
import com.google.gerrit.server.project.RefFilter;
import com.google.inject.Inject;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Base64;
import java.util.Comparator;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.TreeMap;
import java.util.stream.Collectors;
import org.eclipse.jgit.errors.RepositoryNotFoundException;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.kohsuke.args4j.Option;
public class ListBranches implements RestReadView {
public static final String NEXT_PAGE_TOKEN_HEADER = "X-GERRIT-NEXT-PAGE-TOKEN";
private static final String ENCODED_HEADER = encodeImpl(NEXT_PAGE_TOKEN_HEADER);
private static final RefNameComparator REF_NAME_COMPARATOR = new RefNameComparator();
private final GitRepositoryManager repoManager;
private final PermissionBackend permissionBackend;
private final DynamicMap> branchViews;
private final UiActions uiActions;
private final WebLinks webLinks;
@Option(
name = "--limit",
aliases = {"-n"},
metaVar = "CNT",
usage = "maximum number of branches to list")
public void setLimit(int limit) {
this.limit = limit;
}
@Option(
name = "--start",
aliases = {"-S", "-s"},
metaVar = "CNT",
usage = "number of branches to skip")
public void setStart(int start) {
this.start = start;
}
@Option(
name = "--next-page-token",
aliases = {"-t"},
metaVar = "CNT",
usage = "continuation token that can be used to skip some branches")
public void setNextPageToken(String token) {
this.nextPageToken = token;
}
@Option(
name = "--match",
aliases = {"-m"},
metaVar = "MATCH",
usage = "match branches substring")
public void setMatchSubstring(String matchSubstring) {
this.matchSubstring = matchSubstring;
}
@Option(
name = "--regex",
aliases = {"-r"},
metaVar = "REGEX",
usage = "match branches regex")
public void setMatchRegex(String matchRegex) {
this.matchRegex = matchRegex;
}
private int limit;
private int start;
private String nextPageToken;
private String matchSubstring;
private String matchRegex;
@Inject
public ListBranches(
GitRepositoryManager repoManager,
PermissionBackend permissionBackend,
DynamicMap> branchViews,
UiActions uiActions,
WebLinks webLinks) {
this.repoManager = repoManager;
this.permissionBackend = permissionBackend;
this.branchViews = branchViews;
this.uiActions = uiActions;
this.webLinks = webLinks;
}
public ListBranches request(ListRefsRequest request) {
this.setLimit(request.getLimit());
this.setStart(request.getStart());
this.setNextPageToken(request.getNextPageToken());
this.setMatchSubstring(request.getSubstring());
this.setMatchRegex(request.getRegex());
return this;
}
@AutoValue
abstract static class ListBranchResult {
/** List of branches in the result set. */
abstract ImmutableList list();
/** Indicates if there are more results. */
abstract boolean hasMore();
static ListBranchResult create(ImmutableList list, boolean hasMore) {
return new AutoValue_ListBranches_ListBranchResult(list, hasMore);
}
}
@Override
public Response> apply(ProjectResource rsrc)
throws RestApiException, IOException, PermissionBackendException {
rsrc.getProjectState().checkStatePermitsRead();
if (start > 0 && nextPageToken != null) {
throw new BadRequestException(
"'start' and 'next-page-token' parameters are mutually exclusive.");
}
// Filter on refs/heads/*, substring and regex without checking ref visibility
List allBranches = readAllBranches(rsrc);
Set targets = getTargets(allBranches);
ImmutableList filtered =
new RefFilter<>(Constants.R_HEADS, (Ref r) -> r.getName())
.subString(matchSubstring).regex(matchRegex).filter(allBranches).stream()
.sorted(new RefComparator())
.collect(ImmutableList.toImmutableList());
if (nextPageToken != null) {
if (!isValidToken(nextPageToken)) {
throw new BadRequestException(
"Invalid 'next-page-token'. This token was not created by the Gerrit server.");
}
filtered = filterUsingNextPageToken(filtered);
}
// Filter for visibility, taking 'start' and 'limit' parameters into account
ListBranchResult result = filterForVisibility(rsrc, filtered, targets);
return result.hasMore()
? Response.ok(
result.list(),
ImmutableMultimap.of(
NEXT_PAGE_TOKEN_HEADER,
encodeToken(result.list().get(result.list().size() - 1).ref)))
: Response.ok(result.list());
}
BranchInfo toBranchInfo(BranchResource rsrc)
throws IOException, ResourceNotFoundException, PermissionBackendException {
try (Repository db = repoManager.openRepository(rsrc.getNameKey())) {
String refName = rsrc.getRef();
if (RefNames.isRefsUsersSelf(refName, rsrc.getProjectState().isAllUsers())) {
refName = RefNames.refsUsers(rsrc.getUser().getAccountId());
}
Ref r = db.exactRef(refName);
if (r == null) {
throw new ResourceNotFoundException();
}
return toBranchInfo(
r,
getTargets(ImmutableList.of(r)),
rsrc.getNameKey(),
rsrc.getProjectState(),
rsrc.getUser())
.get();
} catch (RepositoryNotFoundException noRepo) {
throw new ResourceNotFoundException(rsrc.getNameKey().get(), noRepo);
}
}
private List readAllBranches(ProjectResource rsrc)
throws IOException, ResourceNotFoundException {
List refs;
try (Repository db = repoManager.openRepository(rsrc.getNameKey())) {
List heads = db.getRefDatabase().getRefsByPrefix(Constants.R_HEADS);
refs = new ArrayList<>(heads.size() + 3);
refs.addAll(heads);
refs.addAll(
db.getRefDatabase()
.exactRef(Constants.HEAD, RefNames.REFS_CONFIG, RefNames.REFS_USERS_DEFAULT)
.values());
return refs;
} catch (RepositoryNotFoundException noGitRepository) {
throw new ResourceNotFoundException(rsrc.getNameKey().get(), noGitRepository);
}
}
/**
* Filter the input {@code refs} list w.r.t. current user's visibility of the ref. This also takes
* into account the {@link #start} and {@link #limit} parameters. We check refs iteratively while
* keeping track of matching (visible) refs. We only populate the output list if the matching ref
* ordinal is greater or equal {@link #start} and keep filling the output list until a {@link
* #limit} number of refs is gotten.
*/
private ListBranchResult filterForVisibility(
ProjectResource rsrc, List refs, Set targets) throws PermissionBackendException {
List branches = new ArrayList<>();
boolean hasMore = false;
int matchingRefs = 0;
for (Ref ref : refs) {
Optional info =
toBranchInfo(ref, targets, rsrc.getNameKey(), rsrc.getProjectState(), rsrc.getUser());
if (info.isPresent()) {
matchingRefs += 1;
if (matchingRefs > start) {
branches.add(info.get());
}
if (limit > 0 && branches.size() == limit + 1) {
// Break and return earlier if we've already found 'limit' refs. The processing of the
// remaining refs for visibility is not needed anymore.
hasMore = true;
break;
}
}
}
if (hasMore && branches.size() >= 1) {
branches = branches.subList(0, branches.size() - 1);
}
return ListBranchResult.create(ImmutableList.copyOf(branches), hasMore);
}
/**
* Filter input list by seeking directly to the first item after the ref identified by {@link
* #nextPageToken}. As a precondition, the {@code inputRefs} should be sorted using {@link
* #REF_NAME_COMPARATOR}.
*/
private ImmutableList filterUsingNextPageToken(List inputRefs)
throws BadRequestException {
try {
nextPageToken = decodeToken(nextPageToken);
} catch (IllegalArgumentException e) {
throw new BadRequestException("Invalid 'next-page-token'.", e);
}
List refNames = inputRefs.stream().map(Ref::getName).collect(Collectors.toList());
// Seek to the next item after token
int nextItemIdx =
Arrays.binarySearch(
refNames.toArray(new String[refNames.size()]), nextPageToken, REF_NAME_COMPARATOR);
if (nextItemIdx == inputRefs.size()) {
return ImmutableList.of();
} else if (nextItemIdx < 0) {
// The item did not exist and binary search returned -(insertion point) - 1. Convert to
// the correct value.
nextItemIdx = -nextItemIdx - 1;
} else if (inputRefs.get(nextItemIdx).getName().equals(nextPageToken)) {
// Binary search returns the index of the element if it exists. If so, increase the index
// by 1 to point to the next element.
nextItemIdx += 1;
}
return inputRefs.subList(nextItemIdx, inputRefs.size()).stream()
.collect(ImmutableList.toImmutableList());
}
/**
* Returns a {@link BranchInfo} if the branch is visible to the caller or {@link Optional#empty()}
* otherwise.
*/
private Optional toBranchInfo(
Ref ref,
Set targets,
Project.NameKey project,
ProjectState projectState,
CurrentUser currentUser)
throws PermissionBackendException {
PermissionBackend.ForProject perm = permissionBackend.currentUser().project(project);
if (ref.isSymbolic()) {
// A symbolic reference to another branch, instead of
// showing the resolved value, show the name it references.
//
String target = ref.getTarget().getName();
try {
perm.ref(target).check(RefPermission.READ);
} catch (AuthException e) {
return Optional.empty();
}
if (target.startsWith(Constants.R_HEADS)) {
target = target.substring(Constants.R_HEADS.length());
}
BranchInfo info = new BranchInfo();
info.ref = ref.getName();
info.revision = target;
if (!Constants.HEAD.equals(ref.getName())) {
if (isConfigRef(ref.getName())) {
// Never allow to delete the meta config branch.
info.canDelete = null;
} else {
info.canDelete =
(perm.ref(ref.getName()).testOrFalse(RefPermission.DELETE)
&& projectState.statePermitsWrite())
? true
: null;
}
}
return Optional.of(info);
}
try {
perm.ref(ref.getName()).check(RefPermission.READ);
BranchInfo branchInfo =
createBranchInfo(perm.ref(ref.getName()), ref, projectState, currentUser, targets);
return Optional.of(branchInfo);
} catch (AuthException e) {
// Do nothing.
return Optional.empty();
}
}
private static Set getTargets(List refs) {
Set targets = Sets.newHashSetWithExpectedSize(1);
refs.stream().filter(Ref::isSymbolic).forEach(r -> targets.add(r.getTarget().getName()));
return targets;
}
private static class RefComparator implements Comparator {
@Override
public int compare(Ref a, Ref b) {
return REF_NAME_COMPARATOR.compare(a.getName(), b.getName());
}
}
private static class RefNameComparator implements Comparator {
@Override
public int compare(String a, String b) {
return ComparisonChain.start()
.compareTrueFirst(isHead(a), isHead(b))
.compareTrueFirst(isConfig(a), isConfig(b))
.compare(a, b)
.result();
}
private static boolean isHead(String r) {
return Constants.HEAD.equals(r);
}
private static boolean isConfig(String r) {
return RefNames.REFS_CONFIG.equals(r);
}
}
private BranchInfo createBranchInfo(
PermissionBackend.ForRef perm,
Ref ref,
ProjectState projectState,
CurrentUser user,
Set targets) {
BranchInfo info = new BranchInfo();
info.ref = ref.getName();
info.revision = ref.getObjectId() != null ? ref.getObjectId().name() : null;
if (isConfigRef(ref.getName())) {
// Never allow to delete the meta config branch.
info.canDelete = null;
} else {
info.canDelete =
(!targets.contains(ref.getName())
&& perm.testOrFalse(RefPermission.DELETE)
&& projectState.statePermitsWrite())
? true
: null;
}
BranchResource rsrc = new BranchResource(projectState, user, ref);
for (UiAction.Description d : uiActions.from(branchViews, rsrc)) {
if (info.actions == null) {
info.actions = new TreeMap<>();
}
info.actions.put(d.getId(), new ActionInfo(d));
}
ImmutableList links =
webLinks.getBranchLinks(projectState.getName(), ref.getName());
info.webLinks = links.isEmpty() ? null : links;
return info;
}
/** Encodes the {@link #nextPageToken} using proto serialization followed by based64 encoding. */
@VisibleForTesting
public static String encodeToken(String token) {
// The encoding of the header is prepended as a method to validate that this token was generated
// by the Gerrit server.
return ENCODED_HEADER + encodeImpl(token);
}
private static String encodeImpl(String token) {
return new String(
Base64.getEncoder()
.encode(
Protos.toByteArray(PaginationToken.newBuilder().setNextPageToken(token).build())),
StandardCharsets.UTF_8);
}
/** Validates that the token was encoded by the Gerrit server. */
private static boolean isValidToken(String token) {
return token.startsWith(ENCODED_HEADER);
}
/**
* Decodes the {@link #nextPageToken}. Callers should validate the token with the {@link
* #isValidToken(String)} method first.
*/
private static String decodeToken(String encoded) {
encoded = encoded.substring(ENCODED_HEADER.length());
return Protos.parseUnchecked(PaginationToken.parser(), Base64.getDecoder().decode(encoded))
.getNextPageToken();
}
}