/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2002, 2015 Oracle and/or its affiliates. All rights reserved.
*
*/
package com.sleepycat.persist.impl;
import java.util.ArrayList;
import java.util.IdentityHashMap;
import java.util.List;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import com.sleepycat.compat.DbCompat;
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.Transaction;
import com.sleepycat.persist.evolve.Converter;
import com.sleepycat.persist.evolve.Deleter;
import com.sleepycat.persist.evolve.Mutation;
import com.sleepycat.persist.evolve.Mutations;
import com.sleepycat.persist.evolve.Renamer;
import com.sleepycat.persist.model.SecondaryKeyMetadata;
/**
* Evolves each old format that is still relevant if necessary, using Mutations
* to configure deleters, renamers, and converters.
*
* @author Mark Hayes
*/
class Evolver {
static final int EVOLVE_NONE = 0;
static final int EVOLVE_NEEDED = 1;
static final int EVOLVE_FAILURE = 2;
private PersistCatalog catalog;
private String storePrefix;
private Mutations mutations;
private Map<String, Format> newFormats;
private boolean forceEvolution;
private boolean disallowClassChanges;
private boolean nestedFormatsChanged;
private Map<Format, Format> changedFormats;
private StringBuilder errors;
private Set<String> deleteDbs;
private Map<String, String> renameDbs;
private Map<Format, Format> renameFormats;
private Map<Integer, Boolean> evolvedFormats;
private List<Format> unprocessedFormats;
private Map<Format, Set<Format>> subclassMap;
Evolver(PersistCatalog catalog,
String storePrefix,
Mutations mutations,
Map<String, Format> newFormats,
boolean forceEvolution,
boolean disallowClassChanges) {
this.catalog = catalog;
this.storePrefix = storePrefix;
this.mutations = mutations;
this.newFormats = newFormats;
this.forceEvolution = forceEvolution;
this.disallowClassChanges = disallowClassChanges;
changedFormats = new IdentityHashMap<Format, Format>();
errors = new StringBuilder();
deleteDbs = new HashSet<String>();
renameDbs = new HashMap<String, String>();
renameFormats = new IdentityHashMap<Format, Format>();
evolvedFormats = new HashMap<Integer, Boolean>();
unprocessedFormats = new ArrayList<Format>();
subclassMap = catalog.getSubclassMap();
}
final Mutations getMutations() {
return mutations;
}
/**
* Returns whether any formats were changed during evolution, and therefore
* need to be stored in the catalog.
*/
boolean areFormatsChanged() {
return !changedFormats.isEmpty();
}
/**
* Returns whether the given format was changed during evolution.
*/
boolean isFormatChanged(Format format) {
return changedFormats.containsKey(format);
}
private void setFormatsChanged(Format oldFormat) {
checkClassChangesAllowed(oldFormat);
changedFormats.put(oldFormat, oldFormat);
nestedFormatsChanged = true;
/* PersistCatalog.expectNoClassChanges is true in unit tests only. */
if (PersistCatalog.expectNoClassChanges) {
throw new IllegalStateException("expectNoClassChanges");
}
}
private void checkClassChangesAllowed(Format oldFormat) {
if (disallowClassChanges) {
throw new IllegalStateException
("When performing an upgrade changes are not allowed " +
"but were made to: " + oldFormat.getClassName());
}
}
/**
* Returns the set of formats for a specific superclass format, or null if
* the superclass is not a complex type or has not subclasses.
*/
Set<Format> getSubclassFormats(Format superFormat) {
return subclassMap.get(superFormat);
}
/**
* Returns an error string if any mutations are invalid or missing, or
* returns null otherwise. If non-null is returned, the store may not be
* opened.
*/
String getErrors() {
if (errors.length() > 0) {
return errors.toString() + "\n---\n" +
"(Note that when upgrading an application in a replicated " +
"environment, this exception may indicate that the Master " +
"was mistakenly upgraded before this Replica could be " +
"upgraded, and the solution is to upgrade this Replica.)";
} else {
return null;
}
}
/**
* Adds a newline and the given error.
*/
private void addError(String error) {
if (errors.length() > 0) {
errors.append("\n---\n");
}
errors.append(error);
}
private String getClassVersionLabel(Format format, String prefix) {
if (format != null) {
return prefix +
" class: " + format.getClassName() +
" version: " + format.getVersion();
} else {
return "";
}
}
/**
* Adds a specified error when no specific mutation is involved.
*/
void addEvolveError(Format oldFormat,
Format newFormat,
String scenario,
String error) {
checkClassChangesAllowed(oldFormat);
if (scenario == null) {
scenario = "Error";
}
addError(scenario + " when evolving" +
getClassVersionLabel(oldFormat, "") +
getClassVersionLabel(newFormat, " to") +
" Error: " + error);
}
/**
* Adds an error for an invalid mutation.
*/
void addInvalidMutation(Format oldFormat,
Format newFormat,
Mutation mutation,
String error) {
checkClassChangesAllowed(oldFormat);
addError("Invalid mutation: " + mutation +
getClassVersionLabel(oldFormat, " For") +
getClassVersionLabel(newFormat, " New") +
" Error: " + error);
}
/**
* Adds an error for a missing mutation.
*/
void addMissingMutation(Format oldFormat,
Format newFormat,
String error) {
checkClassChangesAllowed(oldFormat);
addError("Mutation is missing to evolve" +
getClassVersionLabel(oldFormat, "") +
getClassVersionLabel(newFormat, " to") +
" Error: " + error);
}
/**
* Called by PersistCatalog for all non-entity formats.
*/
void addNonEntityFormat(Format oldFormat) {
unprocessedFormats.add(oldFormat);
}
/**
* Called by PersistCatalog after calling evolveFormat or
* addNonEntityFormat for all old formats.
*
* We do not require deletion of an unreferenced class for two
* reasons: 1) built-in proxy classes may not be referenced, 2) the
* user may wish to declare persistent classes that are not yet used.
*/
void finishEvolution() {
/* Process unreferenced classes. */
for (Format oldFormat : unprocessedFormats) {
oldFormat.setUnused(true);
evolveFormat(oldFormat);
}
}
/**
* Called by PersistCatalog for all entity formats, and by Format.evolve
* methods for all potentially referenced non-entity formats.
*/
boolean evolveFormat(Format oldFormat) {
if (oldFormat.isNew()) {
return true;
}
boolean result;
Format oldEntityFormat = oldFormat.getEntityFormat();
boolean trackEntityChanges = oldEntityFormat != null;
boolean saveNestedFormatsChanged = nestedFormatsChanged;
if (trackEntityChanges) {
nestedFormatsChanged = false;
}
Integer oldFormatId = oldFormat.getId();
if (evolvedFormats.containsKey(oldFormatId)) {
result = evolvedFormats.get(oldFormatId);
} else {
evolvedFormats.put(oldFormatId, true);
result = evolveFormatInternal(oldFormat);
evolvedFormats.put(oldFormatId, result);
}
if (oldFormat.getLatestVersion().isNew()) {
nestedFormatsChanged = true;
}
if (trackEntityChanges) {
if (nestedFormatsChanged) {
Format latest = oldEntityFormat.getLatestVersion();
if (latest != null) {
latest.setEvolveNeeded(true);
}
}
nestedFormatsChanged = saveNestedFormatsChanged;
}
return result;
}
/**
* Tries to evolve a given existing format to the current version of the
* class and returns false if an invalid mutation is encountered or the
* configured mutations are not sufficient.
*/
private boolean evolveFormatInternal(Format oldFormat) {
/* Predefined formats and deleted classes never need evolving. */
if (Format.isPredefined(oldFormat) || oldFormat.isDeleted()) {
return true;
}
/* Get class mutations. */
String oldName = oldFormat.getClassName();
int oldVersion = oldFormat.getVersion();
Renamer renamer = mutations.getRenamer(oldName, oldVersion, null);
Deleter deleter = mutations.getDeleter(oldName, oldVersion, null);
Converter converter =
mutations.getConverter(oldName, oldVersion, null);
if (deleter != null && (converter != null || renamer != null)) {
addInvalidMutation
(oldFormat, null, deleter,
"Class Deleter not allowed along with a Renamer or " +
"Converter for the same class");
return false;
}
/*
* For determining the new name, arrays get special treatment. The
* component format is evolved in the process, and we disallow muations
* for arrays.
*/
String newName;
if (oldFormat.isArray()) {
if (deleter != null || converter != null || renamer != null) {
Mutation mutation = (deleter != null) ? deleter :
((converter != null) ? converter : renamer);
addInvalidMutation
(oldFormat, null, mutation,
"Mutations not allowed for an array");
return false;
}
Format compFormat = oldFormat.getComponentType();
if (!evolveFormat(compFormat)) {
return false;
}
Format latest = compFormat.getLatestVersion();
if (latest != compFormat) {
newName = (latest.isArray() ? "[" : "[L") +
latest.getClassName() + ';';
} else {
newName = oldName;
}
} else {
newName = (renamer != null) ? renamer.getNewName() : oldName;
}
/* Try to get the new class format. Save exception for later. */
Format newFormat;
String newFormatException;
try {
Class newClass = catalog.resolveClass(newName);
try {
newFormat = catalog.createFormat(newClass, newFormats);
assert newFormat != oldFormat : newFormat.getClassName();
newFormatException = null;
} catch (Exception e) {
newFormat = null;
newFormatException = e.toString();
}
} catch (ClassNotFoundException e) {
newFormat = null;
newFormatException = e.toString();
}
if (newFormat != null) {
/*
* If the old format is not the existing latest version and the new
* format is not an existing format, then we must evolve the latest
* old version to the new format first. We cannot evolve old
* format to a new format that may be discarded because it is equal
* to the latest existing format (which will remain the current
* version).
*/
if (oldFormat != oldFormat.getLatestVersion() &&
newFormat.getPreviousVersion() == null) {
assert newFormats.containsValue(newFormat);
Format oldLatestFormat = oldFormat.getLatestVersion();
if (!evolveFormat(oldLatestFormat)) {
return false;
}
if (oldLatestFormat == oldLatestFormat.getLatestVersion()) {
/* newFormat is no longer relevant [#21869]. */
newFormats.remove(newFormat.getClassName());
newFormat = oldLatestFormat;
}
}
/*
* If the old format was previously evolved to the new format
* (which means the new format is actually an existing format),
* then there is nothing to do. This is the case where no class
* changes were made.
*
* However, if mutations were specified when opening the catalog
* that are different than the mutations last used, then we must
* force the re-evolution of all old formats.
*/
if (!forceEvolution &&
newFormat == oldFormat.getLatestVersion()) {
return true;
}
}
/* Apply class Renamer and continue if successful. */
if (renamer != null) {
if (!applyClassRenamer(renamer, oldFormat, newFormat)) {
return false;
}
}
/* Apply class Converter and return. */
if (converter != null) {
if (oldFormat.isEntity()) {
if (newFormat == null || !newFormat.isEntity()) {
addInvalidMutation
(oldFormat, newFormat, converter,
"Class converter not allowed for an entity class " +
"that is no longer present or not having an " +
"@Entity annotation");
return false;
}
if (!oldFormat.evolveMetadata(newFormat, converter, this)) {
return false;
}
}
return applyConverter(converter, oldFormat, newFormat);
}
/* Apply class Deleter and return. */
boolean needDeleter =
(newFormat == null) ||
(newFormat.isEntity() != oldFormat.isEntity());
if (deleter != null) {
if (!needDeleter) {
addInvalidMutation
(oldFormat, newFormat, deleter,
"Class deleter not allowed when the class and its " +
"@Entity or @Persistent annotation is still present");
return false;
}
return applyClassDeleter(deleter, oldFormat, newFormat);
} else {
if (needDeleter) {
if (newFormat == null) {
assert newFormatException != null;
/* FindBugs newFormat known to be null excluded. */
addMissingMutation
(oldFormat, newFormat, newFormatException);
} else {
addMissingMutation
(oldFormat, newFormat,
"@Entity switched to/from @Persistent");
}
return false;
}
}
/*
* Class-level mutations have been applied. Now apply field mutations
* (for complex classes) or special conversions (enum conversions, for
* example) by calling the old format's evolve method.
*/
return oldFormat.evolve(newFormat, this);
}
/**
* Use the old format and discard the new format. Called by
* Format.evolve when the old and new formats are identical.
*/
void useOldFormat(Format oldFormat, Format newFormat) {
Format renamedFormat = renameFormats.get(oldFormat);
if (renamedFormat != null) {
/*
* The format was renamed but, because this method is called, we
* know that no other class changes were made. Use the new/renamed
* format as the reader.
*/
assert renamedFormat == newFormat;
useEvolvedFormat(oldFormat, renamedFormat, renamedFormat);
} else if (newFormat != null &&
(oldFormat.getVersion() != newFormat.getVersion() ||
!oldFormat.isCurrentVersion())) {
/*
* If the user wants a new version number, but ther are no other
* changes, we will oblige. Or, if an attempt is being made to
* use an old version, then the following events happened and we
* must evolve the old format:
* 1) The (previously) latest version of the format was evolved
* because it is not equal to the live class version. Note that
* evolveFormatInternal always evolves the latest version first.
* 2) We are now attempting to evolve an older version of the same
* format, and it happens to be equal to the live class version.
* However, we're already committed to the new format, and we must
* evolve all versions.
* [#16467]
*/
useEvolvedFormat(oldFormat, newFormat, newFormat);
} else {
/* The new format is discarded. */
catalog.useExistingFormat(oldFormat);
if (newFormat != null) {
newFormats.remove(newFormat.getClassName());
}
}
}
/**
* Install an evolver Reader in the old format. Called by Format.evolve
* when the old and new formats are not identical.
*/
void useEvolvedFormat(Format oldFormat,
Reader evolveReader,
Format newFormat) {
oldFormat.setReader(evolveReader);
if (newFormat != null) {
oldFormat.setLatestVersion(newFormat);
}
setFormatsChanged(oldFormat);
}
private boolean applyClassRenamer(Renamer renamer,
Format oldFormat,
Format newFormat) {
if (!checkUpdatedVersion(renamer, oldFormat, newFormat)) {
return false;
}
if (oldFormat.isEntity() && oldFormat.isCurrentVersion()) {
String newClassName = newFormat.getClassName();
String oldClassName = oldFormat.getClassName();
/* Queue the renaming of the primary and secondary databases. */
renameDbs.put
(Store.makePriDbName(storePrefix, oldClassName),
Store.makePriDbName(storePrefix, newClassName));
for (SecondaryKeyMetadata keyMeta :
oldFormat.getEntityMetadata().getSecondaryKeys().values()) {
String keyName = keyMeta.getKeyName();
renameDbs.put
(Store.makeSecDbName(storePrefix, oldClassName, keyName),
Store.makeSecDbName(storePrefix, newClassName, keyName));
}
}
/*
* Link the old format to the renamed format so that we can detect the
* rename in useOldFormat.
*/
renameFormats.put(oldFormat, newFormat);
setFormatsChanged(oldFormat);
return true;
}
/**
* Called by ComplexFormat when a secondary key name is changed.
*/
void renameSecondaryDatabase(String oldEntityClass,
String newEntityClass,
String oldKeyName,
String newKeyName) {
renameDbs.put
(Store.makeSecDbName(storePrefix, oldEntityClass, oldKeyName),
Store.makeSecDbName(storePrefix, newEntityClass, newKeyName));
}
private boolean applyClassDeleter(Deleter deleter,
Format oldFormat,
Format newFormat) {
if (!checkUpdatedVersion(deleter, oldFormat, newFormat)) {
return false;
}
if (oldFormat.isEntity() && oldFormat.isCurrentVersion()) {
/* Queue the deletion of the primary and secondary databases. */
String className = oldFormat.getClassName();
deleteDbs.add(Store.makePriDbName(storePrefix, className));
for (SecondaryKeyMetadata keyMeta :
oldFormat.getEntityMetadata().getSecondaryKeys().values()) {
deleteDbs.add(Store.makeSecDbName
(storePrefix, className, keyMeta.getKeyName()));
}
}
/*
* Set the format to deleted last, so that the above test using
* isCurrentVersion works properly.
*/
oldFormat.setDeleted(true);
if (newFormat != null) {
oldFormat.setLatestVersion(newFormat);
}
setFormatsChanged(oldFormat);
return true;
}
/**
* Called by ComplexFormat when a secondary key is dropped.
*/
void deleteSecondaryDatabase(String oldEntityClass, String keyName) {
deleteDbs.add(Store.makeSecDbName
(storePrefix, oldEntityClass, keyName));
}
private boolean applyConverter(Converter converter,
Format oldFormat,
Format newFormat) {
if (!checkUpdatedVersion(converter, oldFormat, newFormat)) {
return false;
}
Reader reader = new ConverterReader(converter);
useEvolvedFormat(oldFormat, reader, newFormat);
return true;
}
boolean isClassConverted(Format format) {
return format.getReader() instanceof ConverterReader;
}
private boolean checkUpdatedVersion(Mutation mutation,
Format oldFormat,
Format newFormat) {
if (newFormat != null &&
!oldFormat.isEnum() &&
newFormat.getVersion() <= oldFormat.getVersion()) {
addInvalidMutation
(oldFormat, newFormat, mutation,
"A new higher version number must be assigned");
return false;
} else {
return true;
}
}
boolean checkUpdatedVersion(String scenario,
Format oldFormat,
Format newFormat) {
if (newFormat != null &&
!oldFormat.isEnum() &&
newFormat.getVersion() <= oldFormat.getVersion()) {
addEvolveError
(oldFormat, newFormat, scenario,
"A new higher version number must be assigned");
return false;
} else {
return true;
}
}
void renameAndRemoveDatabases(Store store, Transaction txn)
throws DatabaseException {
for (String dbName : deleteDbs) {
String[] fileAndDbNames = store.parseDbName(dbName);
/* Do nothing if database does not exist. */
DbCompat.removeDatabase
(store.getEnvironment(), txn,
fileAndDbNames[0], fileAndDbNames[1]);
}
/*
* An importunate locker must be used to rename databases, since rename
* with Database handles open is not currently possible. This is the
* same sort of operation as performed by the HA replayer. If the
* evolution (and rename here) occurs in a replication group upgrade,
* this will cause DatabasePreemptedException the next time the
* database is accessed (via the store or otherwise). In a standalone
* environment, this won't happen because the database won't be open;
* evolve occurs before opening the database in this case. [#16655]
*/
boolean saveImportunate = false;
if (txn != null) {
saveImportunate = DbCompat.setImportunate(txn, true);
}
try {
for (Map.Entry<String, String> entry : renameDbs.entrySet()) {
String oldName = entry.getKey();
String newName = entry.getValue();
String[] oldFileAndDbNames = store.parseDbName(oldName);
String[] newFileAndDbNames = store.parseDbName(newName);
/* Do nothing if database does not exist. */
DbCompat.renameDatabase
(store.getEnvironment(), txn,
oldFileAndDbNames[0], oldFileAndDbNames[1],
newFileAndDbNames[0], newFileAndDbNames[1]);
}
} finally {
if (txn != null) {
DbCompat.setImportunate(txn, saveImportunate);
}
}
}
/**
* Evolves a primary key field or composite key field.
*/
int evolveRequiredKeyField(Format oldParent,
Format newParent,
FieldInfo oldField,
FieldInfo newField) {
int result = EVOLVE_NONE;
String oldName = oldField.getName();
final String FIELD_KIND =
"primary key field or composite key class field";
final String FIELD_LABEL =
FIELD_KIND + ": " + oldName;
if (newField == null) {
addMissingMutation
(oldParent, newParent,
"Field is missing and deletion is not allowed for a " +
FIELD_LABEL);
return EVOLVE_FAILURE;
}
/* Check field mutations. Only a Renamer is allowed. */
Deleter deleter = mutations.getDeleter
(oldParent.getClassName(), oldParent.getVersion(), oldName);
if (deleter != null) {
addInvalidMutation
(oldParent, newParent, deleter,
"Deleter is not allowed for a " + FIELD_LABEL);
return EVOLVE_FAILURE;
}
Converter converter = mutations.getConverter
(oldParent.getClassName(), oldParent.getVersion(), oldName);
if (converter != null) {
addInvalidMutation
(oldParent, newParent, converter,
"Converter is not allowed for a " + FIELD_LABEL);
return EVOLVE_FAILURE;
}
Renamer renamer = mutations.getRenamer
(oldParent.getClassName(), oldParent.getVersion(), oldName);
String newName = newField.getName();
if (renamer != null) {
if (!renamer.getNewName().equals(newName)) {
addInvalidMutation
(oldParent, newParent, converter,
"Converter is not allowed for a " + FIELD_LABEL);
return EVOLVE_FAILURE;
}
result = EVOLVE_NEEDED;
} else {
if (!oldName.equals(newName)) {
addMissingMutation
(oldParent, newParent,
"Renamer is required when field name is changed from: " +
oldName + " to: " + newName);
return EVOLVE_FAILURE;
}
}
/*
* Evolve the declared version of the field format.
*/
Format oldFieldFormat = oldField.getType();
if (!evolveFormat(oldFieldFormat)) {
return EVOLVE_FAILURE;
}
Format oldLatestFormat = oldFieldFormat.getLatestVersion();
if (oldFieldFormat != oldLatestFormat) {
result = EVOLVE_NEEDED;
}
Format newFieldFormat = newField.getType();
if (oldLatestFormat.getClassName().equals
(newFieldFormat.getClassName())) {
/* Formats are identical. */
return result;
} else if ((oldLatestFormat.getWrapperFormat() != null &&
oldLatestFormat.getWrapperFormat().getId() ==
newFieldFormat.getId()) ||
(newFieldFormat.getWrapperFormat() != null &&
newFieldFormat.getWrapperFormat().getId() ==
oldLatestFormat.getId())) {
/* Primitive <-> primitive wrapper type change. */
return EVOLVE_NEEDED;
} else {
/* Type was changed incompatibly. */
addEvolveError
(oldParent, newParent,
"Type may not be changed for a " + FIELD_KIND,
"Old field type: " + oldLatestFormat.getClassName() +
" is not compatible with the new type: " +
newFieldFormat.getClassName() +
" for field: " + oldName);
return EVOLVE_FAILURE;
}
}
}