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Read and write model according to the JSON format
/*
* Copyright (c) 2016 University Nice Sophia Antipolis
*
* This file is part of btrplace.
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see > vmsCache = new LinkedHashMap>() {
@Override
protected boolean removeEldestEntry(Map.Entry> foo) {
return size() == DEFAULT_CACHE_SIZE;
}
};
private static Map> nodesCache = new LinkedHashMap>() {
@Override
protected boolean removeEldestEntry(Map.Entry> foo) {
return size() == DEFAULT_CACHE_SIZE;
}
};
/**
* Utility class.
* No instantiation
*/
private JSONs() {
}
/**
* Reset the cache of element sets.
*
* @param size the new cache size
*/
public static void resetCaches(int size) {
nodesCache = new LinkedHashMap>() {
@Override
protected boolean removeEldestEntry(Map.Entry> foo) {
return size() == size;
}
};
vmsCache = new LinkedHashMap>() {
@Override
protected boolean removeEldestEntry(Map.Entry> foo) {
return size() == size;
}
};
}
/**
* Read an expected integer.
*
* @param o the object to parse
* @param id the key in the map that points to an integer
* @return the int
* @throws JSONConverterException if the key does not point to a int
*/
public static int requiredInt(JSONObject o, String id) throws JSONConverterException {
checkKeys(o, id);
try {
return (Integer) o.get(id);
} catch (ClassCastException e) {
throw new JSONConverterException("Unable to read a int from string '" + id + "'", e);
}
}
/**
* Read an optional integer.
*
* @param o the object to parse
* @param id the key in the map that points to an integer
* @param def the default integer value if the key is absent
* @return the resulting integer
* @throws JSONConverterException if the key does not point to a int
*/
public static int optInt(JSONObject o, String id, int def) throws JSONConverterException {
if (o.containsKey(id)) {
try {
return (Integer) o.get(id);
} catch (ClassCastException e) {
throw new JSONConverterException("Unable to read a int from string '" + id + "'", e);
}
}
return def;
}
/**
* Check if some keys are present.
*
* @param o the object to parse
* @param keys the keys to check
* @throws JSONConverterException when at least a key is missing
*/
public static void checkKeys(JSONObject o, String... keys) throws JSONConverterException {
for (String k : keys) {
if (!o.containsKey(k)) {
throw new JSONConverterException("Missing key '" + k + "'");
}
}
}
/**
* Read an expected string.
*
* @param o the object to parse
* @param id the key in the map that points to the string
* @return the string
* @throws JSONConverterException if the key does not point to a string
*/
public static String requiredString(JSONObject o, String id) throws JSONConverterException {
checkKeys(o, id);
Object x = o.get(id);
return x.toString();
}
/**
* Read an expected double.
*
* @param o the object to parse
* @param id the key in the map that points to the double
* @return the double
* @throws JSONConverterException if the key does not point to a double
*/
public static double requiredDouble(JSONObject o, String id) throws JSONConverterException {
checkKeys(o, id);
Object x = o.get(id);
if (!(x instanceof Number)) {
throw new JSONConverterException("Number expected at key '" + id + "' but was '" + x.getClass() + "'.");
}
return ((Number) x).doubleValue();
}
/**
* Read an expected boolean.
*
* @param o the object to parse
* @param id the id in the map that should point to the boolean
* @return the boolean
* @throws org.btrplace.json.JSONConverterException if the key does not point to a boolean
*/
public static boolean requiredBoolean(JSONObject o, String id) throws JSONConverterException {
checkKeys(o, id);
Object x = o.get(id);
if (!(x instanceof Boolean)) {
throw new JSONConverterException("Boolean expected at key '" + id + "' but was '" + x.getClass() + "'.");
}
return (Boolean) x;
}
/**
* Convert an array of VM identifiers to a set of VMs.
* This operation uses a cache of previously converted set of VMs.
* @param mo the associated model to browse
* @param a the json array
* @return the set of VMs
*/
public static List vmsFromJSON(Model mo, JSONArray a) throws JSONConverterException {
String json = a.toJSONString();
List s = vmsCache.get(json);
if (s != null) {
return s;
}
s = new ArrayList<>(a.size());
for (Object o : a) {
s.add(getVM(mo, (int) o));
}
vmsCache.put(json, s);
return s;
}
/**
* Convert an array of VM identifiers to a set of VMs.
* This operation uses a cache of previously converted set of nodes.
* @param mo the associated model to browse
* @param a the json array
* @return the set of nodes
*/
public static List nodesFromJSON(Model mo, JSONArray a) throws JSONConverterException {
String json = a.toJSONString();
List s = nodesCache.get(json);
if (s != null) {
return s;
}
s = new ArrayList<>(a.size());
for (Object o : a) {
s.add(getNode(mo, (int) o));
}
nodesCache.put(json, s);
return s;
}
/**
* Convert a collection of VMs to an array of VM identifiers.
*
* @param s the VMs
* @return a json formatted array of integers
*/
public static JSONArray vmsToJSON(Collection s) {
JSONArray a = new JSONArray();
for (Element e : s) {
a.add(e.id());
}
return a;
}
/**
* Convert a collection nodes to an array of nodes identifiers.
*
* @param s the VMs
* @return a json formatted array of integers
*/
public static JSONArray nodesToJSON(Collection s) {
JSONArray a = new JSONArray();
for (Element e : s) {
a.add(e.id());
}
return a;
}
/**
* Read an expected list of VMs.
*
* @param mo the associated model to browse
* @param o the object to parse
* @param id the key in the map that points to the list
* @return the parsed list
* @throws JSONConverterException if the key does not point to a list of VM identifiers
*/
public static List requiredVMs(Model mo, JSONObject o, String id) throws JSONConverterException {
checkKeys(o, id);
Object x = o.get(id);
if (!(x instanceof JSONArray)) {
throw new JSONConverterException("integers expected at key '" + id + "'");
}
return vmsFromJSON(mo, (JSONArray) x);
}
/**
* Read an expected list of nodes.
*
* @param mo the associated model to browse
* @param o the object to parse
* @param id the key in the map that points to the list
* @return the parsed list
* @throws JSONConverterException if the key does not point to a list of nodes identifiers
*/
public static List requiredNodes(Model mo, JSONObject o, String id) throws JSONConverterException {
checkKeys(o, id);
Object x = o.get(id);
if (!(x instanceof JSONArray)) {
throw new JSONConverterException("integers expected at key '" + id + "'");
}
return nodesFromJSON(mo, (JSONArray) x);
}
/**
* Read partitions of VMs.
*
* @param mo the associated model to browse
* @param o the object to parse
* @param id the key in the map that points to the partitions
* @return the parsed partition
* @throws JSONConverterException if the key does not point to partitions of VMs
*/
public static Set> requiredVMPart(Model mo, JSONObject o, String id) throws JSONConverterException {
Set> vms = new HashSet<>();
Object x = o.get(id);
if (!(x instanceof JSONArray)) {
throw new JSONConverterException("Set of identifiers sets expected at key '" + id + "'");
}
for (Object obj : (JSONArray) x) {
vms.add(vmsFromJSON(mo, (JSONArray) obj));
}
return vms;
}
/**
* Read partitions of nodes.
*
* @param mo the associated model to browse
* @param o the object to parse
* @param id the key in the map that points to the partitions
* @return the parsed partition
* @throws JSONConverterException if the key does not point to partitions of nodes
*/
public static Set> requiredNodePart(Model mo, JSONObject o, String id) throws JSONConverterException {
Set> nodes = new HashSet<>();
Object x = o.get(id);
if (!(x instanceof JSONArray)) {
throw new JSONConverterException("Set of identifiers sets expected at key '" + id + "'");
}
for (Object obj : (JSONArray) x) {
nodes.add(nodesFromJSON(mo, (JSONArray) obj));
}
return nodes;
}
/**
* Read an expected VM.
*
* @param mo the associated model to browse
* @param o the object to parse
* @param id the key in the map that points to the VM identifier
* @return the VM
* @throws JSONConverterException if the key does not point to a VM identifier
*/
public static VM requiredVM(Model mo, JSONObject o, String id) throws JSONConverterException {
checkKeys(o, id);
try {
return getVM(mo, (Integer) o.get(id));
} catch (ClassCastException e) {
throw new JSONConverterException("Unable to read a VM identifier from string at key '" + id + "'", e);
}
}
/**
* Read an expected node.
*
* @param mo the associated model to browse
* @param o the object to parse
* @param id the key in the map that points to the node identifier
* @return the node
* @throws JSONConverterException if the key does not point to a node identifier
*/
public static Node requiredNode(Model mo, JSONObject o, String id) throws JSONConverterException {
checkKeys(o, id);
try {
return getNode(mo, (Integer) o.get(id));
} catch (ClassCastException e) {
throw new JSONConverterException("Unable to read a Node identifier from string at key '" + id + "'", e);
}
}
/**
* Get a VM from its identifier.
* The VM is already a part of the model.
*
* @param mo the associated model to browse
* @param vmID the node identifier
* @return the resulting VM
* @throws JSONConverterException if there is no model, or if the VM is unknown.
*/
public static VM getVM(Model mo, int vmID) throws JSONConverterException {
VM vm = new VM(vmID);
if (!mo.contains(vm)) {
throw new JSONConverterException("Undeclared vm '" + vmID + "'");
}
return vm;
}
/**
* Get a node from its identifier.
* The node is already a part of the model
*
* @param mo the associated model to browse
* @param nodeID the node identifier
* @return the resulting node
* @throws JSONConverterException if there is no model, or if the node is unknown.
*/
public static Node getNode(Model mo, int nodeID) throws JSONConverterException {
Node n = new Node(nodeID);
if (!mo.contains(n)) {
throw new JSONConverterException("Undeclared node '" + nodeID + "'");
}
return n;
}
/**
* Get an element identifier.
*
* @param e the element
* @return its identifier
*/
public static Integer elementToJSON(Element e) {
return e.id();
}
}