io.permazen.core.util.ObjDumper Maven / Gradle / Ivy
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/*
* Copyright (C) 2015 Archie L. Cobbs. All rights reserved.
*/
package io.permazen.core.util;
import com.google.common.base.Preconditions;
import io.permazen.core.CounterField;
import io.permazen.core.DeletedObjectException;
import io.permazen.core.Field;
import io.permazen.core.FieldSwitch;
import io.permazen.core.ListField;
import io.permazen.core.MapField;
import io.permazen.core.ObjId;
import io.permazen.core.ObjType;
import io.permazen.core.Schema;
import io.permazen.core.SetField;
import io.permazen.core.SimpleField;
import io.permazen.core.StaleTransactionException;
import io.permazen.core.Transaction;
import io.permazen.core.UnknownTypeException;
import io.permazen.encoding.Encoding;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.NavigableMap;
import java.util.NavigableSet;
/**
* Utility classes for printing database objects and fields in a human-readable format.
*
*
*
*
*
*
* To use this class for implementing {@link Object#toString}, add a method like this to your Java model classes:
*
*
* @Override
* public String toString() {
* return ObjDumper.toString(this.getTransaction().getTransaction(), this.getObjId(), 16);
* }
*
*/
public final class ObjDumper {
private ObjDumper() {
}
/**
* Helper for Java model object {@link Object#toString} methods that wish to display all fields in the object.
*
* @param tx transaction containing the object
* @param id the ID of the object
* @param maxCollectionEntries maximum number of elements to display in any collection field or -1 to not display any fields
* @return contents of the specified object, or just object type and ID if {@code tx} is no longer valid
* @throws IllegalArgumentException if {@code tx} or {@code id} is null
*/
public static String toString(Transaction tx, ObjId id, int maxCollectionEntries) {
// Sanity check
Preconditions.checkArgument(tx != null, "null tx");
Preconditions.checkArgument(id != null, "null id");
// Get object type
final ObjType type;
try {
type = tx.getObjType(id);
} catch (StaleTransactionException e) {
String typeName;
try {
typeName = tx.getSchemaBundle().getObjectTypeName(id.getStorageId());
} catch (IllegalArgumentException e2) {
typeName = String.format("type#%d");
}
return String.format("%s@%s [%s]", typeName, id, "stale tx");
} catch (UnknownTypeException e) {
return String.format("type#%d@%s [%s]", id.getStorageId(), id, "unknown type");
} catch (DeletedObjectException e) {
return String.format("type#%d@%s [%s]", id.getStorageId(), id, "does not exist");
}
// Format object
final StringWriter buf = new StringWriter();
try {
ObjDumper.print(new PrintWriter(buf), tx, id, maxCollectionEntries);
} catch (Exception e) {
buf.write("[exception reading " + type.getName() + "@" + id + ": " + e + "]");
}
// Done
return buf.toString().trim();
}
/**
* Print the content of the given object's fields in a human readable format.
*
*
* The given transaction must still be open and the specified object must exist therein.
*
* @param writer output destination
* @param tx transaction containing the object
* @param id the ID of the object
* @param maxCollectionEntries maximum number of elements to display in any collection field or -1 to not display any fields
* @throws DeletedObjectException if the object does not exist in {@code tx}
* @throws StaleTransactionException if {@code tx} is no longer usable
* @throws UnknownTypeException if {@code id} specifies an unknown object type
* @throws IllegalArgumentException if any parameter is null
*/
public static void print(final PrintWriter writer, final Transaction tx, final ObjId id, final int maxCollectionEntries) {
// Sanity check
Preconditions.checkArgument(writer != null, "null writer");
Preconditions.checkArgument(tx != null, "null tx");
Preconditions.checkArgument(id != null, "null id");
// Get object info
final ObjType type = tx.getObjType(id);
final Schema schema = type.getSchema();
// Print headline
writer.println(String.format("object %s type %s (schema \"%s\")", id, type.getName(), schema.getSchemaId()));
if (maxCollectionEntries < 0) {
writer.flush();
return;
}
// Calculate indent amount
int nameFieldSize = 0;
for (Field field : type.getFields().values())
nameFieldSize = Math.max(nameFieldSize, field.getName().length());
final char[] ichars = new char[nameFieldSize + 3];
Arrays.fill(ichars, ' ');
final String indent = new String(ichars);
final String eindent = indent + " ";
// Display fields
for (Field field : type.getFields().values()) {
writer.print(String.format("%" + nameFieldSize + "s = ", field.getName()));
field.visit(new FieldSwitch() {
@Override
public Void caseSimpleField(SimpleField field) {
final Encoding encoding = field.getEncoding();
final T value = encoding.validate(tx.readSimpleField(id, field.getName(), false));
writer.println(value != null ? "\"" + encoding.toString(value) + "\"" : "null");
return null;
}
@Override
public Void caseCounterField(CounterField field) {
writer.println("" + tx.readCounterField(id, field.getName(), false));
return null;
}
@Override
@SuppressWarnings("unchecked")
public Void caseSetField(SetField field) {
this.handleCollection((NavigableSet)tx.readSetField(id, field.getName(), false),
field.getElementField(), false);
return null;
}
@Override
@SuppressWarnings("unchecked")
public Void caseListField(ListField field) {
this.handleCollection((List)tx.readListField(id, field.getName(), false),
field.getElementField(), true);
return null;
}
private void handleCollection(Collection items, SimpleField elementField, boolean showIndex) {
final Encoding encoding = elementField.getEncoding();
writer.print("{");
int count = 0;
for (E item : items) {
if (count == 0)
writer.println();
if (count >= maxCollectionEntries) {
writer.println(eindent + "...");
count++;
break;
}
writer.print(eindent);
if (showIndex)
writer.print("[" + count + "] ");
writer.println(item != null ? "\"" + encoding.toString(item) + "\"" : "null");
count++;
}
writer.println(count == 0 ? " }" : indent + "}");
}
@Override
@SuppressWarnings("unchecked")
public Void caseMapField(MapField field) {
final Encoding keyEncoding = field.getKeyField().getEncoding();
final Encoding valueEncoding = field.getValueField().getEncoding();
writer.print("{");
int count = 0;
final NavigableMap map = (NavigableMap)tx.readMapField(id, field.getName(), false);
for (Map.Entry entry : map.entrySet()) {
if (count == 0)
writer.println();
if (count >= maxCollectionEntries) {
writer.println(eindent + "...");
count++;
break;
}
final K key = entry.getKey();
final V value = entry.getValue();
final String keyStr = key != null ? "\"" + keyEncoding.toString(key) + "\"" : "null";
final String valueStr = value != null ? "\"" + valueEncoding.toString(value) + "\"" : "null";
writer.println(eindent + keyStr + " -> " + valueStr);
count++;
}
writer.println(count == 0 ? " }" : indent + "}");
return null;
}
});
}
writer.flush();
}
}