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+/*
+ * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
+ *
+ * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
+ * for details.
+ */
+package json.ext;
+
+import org.jruby.Ruby;
+import org.jruby.RubyArray;
+import org.jruby.RubyClass;
+import org.jruby.RubyEncoding;
+import org.jruby.RubyFloat;
+import org.jruby.RubyHash;
+import org.jruby.RubyInteger;
+import org.jruby.RubyModule;
+import org.jruby.RubyNumeric;
+import org.jruby.RubyObject;
+import org.jruby.RubyString;
+import org.jruby.anno.JRubyMethod;
+import org.jruby.exceptions.RaiseException;
+import org.jruby.runtime.Block;
+import org.jruby.runtime.ObjectAllocator;
+import org.jruby.runtime.ThreadContext;
+import org.jruby.runtime.Visibility;
+import org.jruby.runtime.builtin.IRubyObject;
+import org.jruby.util.ByteList;
+
+/**
+ * The <code>JSON::Ext::Parser</code> class.
+ *
+ * <p>This is the JSON parser implemented as a Java class. To use it as the
+ * standard parser, set
+ * <pre>JSON.parser = JSON::Ext::Parser</pre>
+ * This is performed for you when you <code>include "json/ext"</code>.
+ *
+ * <p>This class does not perform the actual parsing, just acts as an interface
+ * to Ruby code. When the {@link #parse()} method is invoked, a
+ * Parser.ParserSession object is instantiated, which handles the process.
+ *
+ * @author mernen
+ */
+public class Parser extends RubyObject {
+ private final RuntimeInfo info;
+ private RubyString vSource;
+ private RubyString createId;
+ private int maxNesting;
+ private boolean allowNaN;
+ private boolean symbolizeNames;
+ private RubyClass objectClass;
+ private RubyClass arrayClass;
+
+ private static final int DEFAULT_MAX_NESTING = 19;
+
+ private static final String JSON_MINUS_INFINITY = "-Infinity";
+ // constant names in the JSON module containing those values
+ private static final String CONST_NAN = "NaN";
+ private static final String CONST_INFINITY = "Infinity";
+ private static final String CONST_MINUS_INFINITY = "MinusInfinity";
+
+ static final ObjectAllocator ALLOCATOR = new ObjectAllocator() {
+ public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
+ return new Parser(runtime, klazz);
+ }
+ };
+
+ /**
+ * Multiple-value return for internal parser methods.
+ *
+ * <p>All the <code>parse<var>Stuff</var></code> methods return instances of
+ * <code>ParserResult</code> when successful, or <code>null</code> when
+ * there's a problem with the input data.
+ */
+ static final class ParserResult {
+ /**
+ * The result of the successful parsing. Should never be
+ * <code>null</code>.
+ */
+ final IRubyObject result;
+ /**
+ * The point where the parser returned.
+ */
+ final int p;
+
+ ParserResult(IRubyObject result, int p) {
+ this.result = result;
+ this.p = p;
+ }
+ }
+
+ public Parser(Ruby runtime, RubyClass metaClass) {
+ super(runtime, metaClass);
+ info = RuntimeInfo.forRuntime(runtime);
+ }
+
+ /**
+ * <code>Parser.new(source, opts = {})</code>
+ *
+ * <p>Creates a new <code>JSON::Ext::Parser</code> instance for the string
+ * <code>source</code>.
+ * It will be configured by the <code>opts</code> Hash.
+ * <code>opts</code> can have the following keys:
+ *
+ * <dl>
+ * <dt><code>:max_nesting</code>
+ * <dd>The maximum depth of nesting allowed in the parsed data
+ * structures. Disable depth checking with <code>:max_nesting => false|nil|0</code>,
+ * it defaults to 19.
+ *
+ * <dt><code>:allow_nan</code>
+ * <dd>If set to <code>true</code>, allow <code>NaN</code>,
+ * <code>Infinity</code> and <code>-Infinity</code> in defiance of RFC 4627
+ * to be parsed by the Parser. This option defaults to <code>false</code>.
+ *
+ * <dt><code>:symbolize_names</code>
+ * <dd>If set to <code>true</code>, returns symbols for the names (keys) in
+ * a JSON object. Otherwise strings are returned, which is also the default.
+ *
+ * <dt><code>:create_additions</code>
+ * <dd>If set to <code>false</code>, the Parser doesn't create additions
+ * even if a matchin class and <code>create_id</code> was found. This option
+ * defaults to <code>true</code>.
+ *
+ * <dt><code>:object_class</code>
+ * <dd>Defaults to Hash.
+ *
+ * <dt><code>:array_class</code>
+ * <dd>Defaults to Array.
+ * </dl>
+ */
+ @JRubyMethod(name = "new", required = 1, optional = 1, meta = true)
+ public static IRubyObject newInstance(IRubyObject clazz, IRubyObject[] args, Block block) {
+ Parser parser = (Parser)((RubyClass)clazz).allocate();
+
+ parser.callInit(args, block);
+
+ return parser;
+ }
+
+ @JRubyMethod(required = 1, optional = 1, visibility = Visibility.PRIVATE)
+ public IRubyObject initialize(ThreadContext context, IRubyObject[] args) {
+ Ruby runtime = context.getRuntime();
+ RubyString source = convertEncoding(context, args[0].convertToString());
+
+ OptionsReader opts =
+ new OptionsReader(context, args.length > 1 ? args[1] : null);
+
+ this.maxNesting = opts.getInt("max_nesting", DEFAULT_MAX_NESTING);
+ this.allowNaN = opts.getBool("allow_nan", false);
+ this.symbolizeNames = opts.getBool("symbolize_names", false);
+ this.createId =
+ opts.getBool("create_additions", true) ? getCreateId(context)
+ : null;
+ this.objectClass = opts.getClass("object_class", runtime.getHash());
+ this.arrayClass = opts.getClass("array_class", runtime.getArray());
+
+ this.vSource = source;
+ return this;
+ }
+
+ /**
+ * Checks the given string's encoding. If a non-UTF-8 encoding is detected,
+ * a converted copy is returned.
+ * Returns the source string if no conversion is needed.
+ */
+ private RubyString convertEncoding(ThreadContext context, RubyString source) {
+ ByteList bl = source.getByteList();
+ int len = bl.length();
+ if (len < 2) {
+ throw Utils.newException(context, Utils.M_PARSER_ERROR,
+ "A JSON text must at least contain two octets!");
+ }
+
+ if (info.encodingsSupported()) {
+ RubyEncoding encoding = (RubyEncoding)source.encoding(context);
+ if (encoding != info.ascii8bit) {
+ return (RubyString)source.encode(context, info.utf8);
+ }
+
+ String sniffedEncoding = sniffByteList(bl);
+ if (sniffedEncoding == null) return source; // assume UTF-8
+ return reinterpretEncoding(context, source, sniffedEncoding);
+ }
+
+ String sniffedEncoding = sniffByteList(bl);
+ if (sniffedEncoding == null) return source; // assume UTF-8
+ Ruby runtime = context.getRuntime();
+ return (RubyString)info.jsonModule.
+ callMethod(context, "iconv",
+ new IRubyObject[] {
+ runtime.newString("utf-8"),
+ runtime.newString(sniffedEncoding),
+ source});
+ }
+
+ /**
+ * Checks the first four bytes of the given ByteList to infer its encoding,
+ * using the principle demonstrated on section 3 of RFC 4627 (JSON).
+ */
+ private static String sniffByteList(ByteList bl) {
+ if (bl.length() < 4) return null;
+ if (bl.get(0) == 0 && bl.get(2) == 0) {
+ return bl.get(1) == 0 ? "utf-32be" : "utf-16be";
+ }
+ if (bl.get(1) == 0 && bl.get(3) == 0) {
+ return bl.get(2) == 0 ? "utf-32le" : "utf-16le";
+ }
+ return null;
+ }
+
+ /**
+ * Assumes the given (binary) RubyString to be in the given encoding, then
+ * converts it to UTF-8.
+ */
+ private RubyString reinterpretEncoding(ThreadContext context,
+ RubyString str, String sniffedEncoding) {
+ RubyEncoding actualEncoding = info.getEncoding(context, sniffedEncoding);
+ RubyEncoding targetEncoding = info.utf8;
+ RubyString dup = (RubyString)str.dup();
+ dup.force_encoding(context, actualEncoding);
+ return (RubyString)dup.encode_bang(context, targetEncoding);
+ }
+
+ /**
+ * <code>Parser#parse()</code>
+ *
+ * <p>Parses the current JSON text <code>source</code> and returns the
+ * complete data structure as a result.
+ */
+ @JRubyMethod
+ public IRubyObject parse(ThreadContext context) {
+ return new ParserSession(this, context).parse();
+ }
+
+ /**
+ * <code>Parser#source()</code>
+ *
+ * <p>Returns a copy of the current <code>source</code> string, that was
+ * used to construct this Parser.
+ */
+ @JRubyMethod(name = "source")
+ public IRubyObject source_get() {
+ return vSource.dup();
+ }
+
+ /**
+ * Queries <code>JSON.create_id</code>. Returns <code>null</code> if it is
+ * set to <code>nil</code> or <code>false</code>, and a String if not.
+ */
+ private RubyString getCreateId(ThreadContext context) {
+ IRubyObject v = info.jsonModule.callMethod(context, "create_id");
+ return v.isTrue() ? v.convertToString() : null;
+ }
+
+ /**
+ * A string parsing session.
+ *
+ * <p>Once a ParserSession is instantiated, the source string should not
+ * change until the parsing is complete. The ParserSession object assumes
+ * the source {@link RubyString} is still associated to its original
+ * {@link ByteList}, which in turn must still be bound to the same
+ * <code>byte[]</code> value (and on the same offset).
+ */
+ // Ragel uses lots of fall-through
+ @SuppressWarnings("fallthrough")
+ private static class ParserSession {
+ private final Parser parser;
+ private final ThreadContext context;
+ private final ByteList byteList;
+ private final byte[] data;
+ private final StringDecoder decoder;
+ private int currentNesting = 0;
+
+ // initialization value for all state variables.
+ // no idea about the origins of this value, ask Flori ;)
+ private static final int EVIL = 0x666;
+
+ private ParserSession(Parser parser, ThreadContext context) {
+ this.parser = parser;
+ this.context = context;
+ this.byteList = parser.vSource.getByteList();
+ this.data = byteList.unsafeBytes();
+ this.decoder = new StringDecoder(context);
+ }
+
+ private RaiseException unexpectedToken(int absStart, int absEnd) {
+ RubyString msg = getRuntime().newString("unexpected token at '")
+ .cat(data, absStart, absEnd - absStart)
+ .cat((byte)'\'');
+ return newException(Utils.M_PARSER_ERROR, msg);
+ }
+
+ private Ruby getRuntime() {
+ return context.getRuntime();
+ }
+
+ %%{
+ machine JSON_common;
+
+ cr = '\n';
+ cr_neg = [^\n];
+ ws = [ \t\r\n];
+ c_comment = '/*' ( any* - (any* '*/' any* ) ) '*/';
+ cpp_comment = '//' cr_neg* cr;
+ comment = c_comment | cpp_comment;
+ ignore = ws | comment;
+ name_separator = ':';
+ value_separator = ',';
+ Vnull = 'null';
+ Vfalse = 'false';
+ Vtrue = 'true';
+ VNaN = 'NaN';
+ VInfinity = 'Infinity';
+ VMinusInfinity = '-Infinity';
+ begin_value = [nft"\-[{NI] | digit;
+ begin_object = '{';
+ end_object = '}';
+ begin_array = '[';
+ end_array = ']';
+ begin_string = '"';
+ begin_name = begin_string;
+ begin_number = digit | '-';
+ }%%
+
+ %%{
+ machine JSON_value;
+ include JSON_common;
+
+ write data;
+
+ action parse_null {
+ result = getRuntime().getNil();
+ }
+ action parse_false {
+ result = getRuntime().getFalse();
+ }
+ action parse_true {
+ result = getRuntime().getTrue();
+ }
+ action parse_nan {
+ if (parser.allowNaN) {
+ result = getConstant(CONST_NAN);
+ } else {
+ throw unexpectedToken(p - 2, pe);
+ }
+ }
+ action parse_infinity {
+ if (parser.allowNaN) {
+ result = getConstant(CONST_INFINITY);
+ } else {
+ throw unexpectedToken(p - 7, pe);
+ }
+ }
+ action parse_number {
+ if (pe > fpc + 9 &&
+ absSubSequence(fpc, fpc + 9).toString().equals(JSON_MINUS_INFINITY)) {
+
+ if (parser.allowNaN) {
+ result = getConstant(CONST_MINUS_INFINITY);
+ fexec p + 10;
+ fhold;
+ fbreak;
+ } else {
+ throw unexpectedToken(p, pe);
+ }
+ }
+ ParserResult res = parseFloat(fpc, pe);
+ if (res != null) {
+ result = res.result;
+ fexec res.p;
+ }
+ res = parseInteger(fpc, pe);
+ if (res != null) {
+ result = res.result;
+ fexec res.p;
+ }
+ fhold;
+ fbreak;
+ }
+ action parse_string {
+ ParserResult res = parseString(fpc, pe);
+ if (res == null) {
+ fhold;
+ fbreak;
+ } else {
+ result = res.result;
+ fexec res.p;
+ }
+ }
+ action parse_array {
+ currentNesting++;
+ ParserResult res = parseArray(fpc, pe);
+ currentNesting--;
+ if (res == null) {
+ fhold;
+ fbreak;
+ } else {
+ result = res.result;
+ fexec res.p;
+ }
+ }
+ action parse_object {
+ currentNesting++;
+ ParserResult res = parseObject(fpc, pe);
+ currentNesting--;
+ if (res == null) {
+ fhold;
+ fbreak;
+ } else {
+ result = res.result;
+ fexec res.p;
+ }
+ }
+ action exit {
+ fhold;
+ fbreak;
+ }
+
+ main := ( Vnull @parse_null |
+ Vfalse @parse_false |
+ Vtrue @parse_true |
+ VNaN @parse_nan |
+ VInfinity @parse_infinity |
+ begin_number >parse_number |
+ begin_string >parse_string |
+ begin_array >parse_array |
+ begin_object >parse_object
+ ) %*exit;
+ }%%
+
+ ParserResult parseValue(int p, int pe) {
+ int cs = EVIL;
+ IRubyObject result = null;
+
+ %% write init;
+ %% write exec;
+
+ if (cs >= JSON_value_first_final && result != null) {
+ return new ParserResult(result, p);
+ } else {
+ return null;
+ }
+ }
+
+ %%{
+ machine JSON_integer;
+
+ write data;
+
+ action exit {
+ fhold;
+ fbreak;
+ }
+
+ main := '-'? ( '0' | [1-9][0-9]* ) ( ^[0-9] @exit );
+ }%%
+
+ ParserResult parseInteger(int p, int pe) {
+ int cs = EVIL;
+
+ %% write init;
+ int memo = p;
+ %% write exec;
+
+ if (cs < JSON_integer_first_final) {
+ return null;
+ }
+
+ ByteList num = absSubSequence(memo, p);
+ // note: this is actually a shared string, but since it is temporary and
+ // read-only, it doesn't really matter
+ RubyString expr = RubyString.newStringLight(getRuntime(), num);
+ RubyInteger number = RubyNumeric.str2inum(getRuntime(), expr, 10, true);
+ return new ParserResult(number, p + 1);
+ }
+
+ %%{
+ machine JSON_float;
+ include JSON_common;
+
+ write data;
+
+ action exit {
+ fhold;
+ fbreak;
+ }
+
+ main := '-'?
+ ( ( ( '0' | [1-9][0-9]* ) '.' [0-9]+ ( [Ee] [+\-]?[0-9]+ )? )
+ | ( ( '0' | [1-9][0-9]* ) ( [Ee] [+\-]? [0-9]+ ) ) )
+ ( ^[0-9Ee.\-] @exit );
+ }%%
+
+ ParserResult parseFloat(int p, int pe) {
+ int cs = EVIL;
+
+ %% write init;
+ int memo = p;
+ %% write exec;
+
+ if (cs < JSON_float_first_final) {
+ return null;
+ }
+
+ ByteList num = absSubSequence(memo, p);
+ // note: this is actually a shared string, but since it is temporary and
+ // read-only, it doesn't really matter
+ RubyString expr = RubyString.newStringLight(getRuntime(), num);
+ RubyFloat number = RubyNumeric.str2fnum(getRuntime(), expr, true);
+ return new ParserResult(number, p + 1);
+ }
+
+ %%{
+ machine JSON_string;
+ include JSON_common;
+
+ write data;
+
+ action parse_string {
+ int offset = byteList.begin();
+ ByteList decoded = decoder.decode(byteList, memo + 1 - offset,
+ p - offset);
+ result = getRuntime().newString(decoded);
+ if (result == null) {
+ fhold;
+ fbreak;
+ } else {
+ fexec p + 1;
+ }
+ }
+
+ action exit {
+ fhold;
+ fbreak;
+ }
+
+ main := '"'
+ ( ( ^(["\\]|0..0x1f)
+ | '\\'["\\/bfnrt]
+ | '\\u'[0-9a-fA-F]{4}
+ | '\\'^(["\\/bfnrtu]|0..0x1f)
+ )* %parse_string
+ ) '"' @exit;
+ }%%
+
+ ParserResult parseString(int p, int pe) {
+ int cs = EVIL;
+ RubyString result = null;
+
+ %% write init;
+ int memo = p;
+ %% write exec;
+
+ if (cs >= JSON_string_first_final && result != null) {
+ return new ParserResult(result, p + 1);
+ } else {
+ return null;
+ }
+ }
+
+ %%{
+ machine JSON_array;
+ include JSON_common;
+
+ write data;
+
+ action parse_value {
+ ParserResult res = parseValue(fpc, pe);
+ if (res == null) {
+ fhold;
+ fbreak;
+ } else {
+ result.append(res.result);
+ fexec res.p;
+ }
+ }
+
+ action exit {
+ fhold;
+ fbreak;
+ }
+
+ next_element = value_separator ignore* begin_value >parse_value;
+
+ main := begin_array
+ ignore*
+ ( ( begin_value >parse_value
+ ignore* )
+ ( ignore*
+ next_element
+ ignore* )* )?
+ ignore*
+ end_array @exit;
+ }%%
+
+ ParserResult parseArray(int p, int pe) {
+ int cs = EVIL;
+
+ if (parser.maxNesting > 0 && currentNesting > parser.maxNesting) {
+ throw newException(Utils.M_NESTING_ERROR,
+ "nesting of " + currentNesting + " is too deep");
+ }
+
+ // this is guaranteed to be a RubyArray due to the earlier
+ // allocator test at OptionsReader#getClass
+ RubyArray result =
+ (RubyArray)parser.arrayClass.newInstance(context,
+ IRubyObject.NULL_ARRAY, Block.NULL_BLOCK);
+
+ %% write init;
+ %% write exec;
+
+ if (cs >= JSON_array_first_final) {
+ return new ParserResult(result, p + 1);
+ } else {
+ throw unexpectedToken(p, pe);
+ }
+ }
+
+ %%{
+ machine JSON_object;
+ include JSON_common;
+
+ write data;
+
+ action parse_value {
+ ParserResult res = parseValue(fpc, pe);
+ if (res == null) {
+ fhold;
+ fbreak;
+ } else {
+ result.op_aset(context, lastName, res.result);
+ fexec res.p;
+ }
+ }
+
+ action parse_name {
+ ParserResult res = parseString(fpc, pe);
+ if (res == null) {
+ fhold;
+ fbreak;
+ } else {
+ RubyString name = (RubyString)res.result;
+ if (parser.symbolizeNames) {
+ lastName = context.getRuntime().is1_9()
+ ? name.intern19()
+ : name.intern();
+ } else {
+ lastName = name;
+ }
+ fexec res.p;
+ }
+ }
+
+ action exit {
+ fhold;
+ fbreak;
+ }
+
+ a_pair = ignore*
+ begin_name >parse_name
+ ignore* name_separator ignore*
+ begin_value >parse_value;
+
+ main := begin_object
+ (a_pair (ignore* value_separator a_pair)*)?
+ ignore* end_object @exit;
+ }%%
+
+ ParserResult parseObject(int p, int pe) {
+ int cs = EVIL;
+ IRubyObject lastName = null;
+
+ if (parser.maxNesting > 0 && currentNesting > parser.maxNesting) {
+ throw newException(Utils.M_NESTING_ERROR,
+ "nesting of " + currentNesting + " is too deep");
+ }
+
+ // this is guaranteed to be a RubyHash due to the earlier
+ // allocator test at OptionsReader#getClass
+ RubyHash result =
+ (RubyHash)parser.objectClass.newInstance(context,
+ IRubyObject.NULL_ARRAY, Block.NULL_BLOCK);
+
+ %% write init;
+ %% write exec;
+
+ if (cs < JSON_object_first_final) {
+ return null;
+ }
+
+ IRubyObject returnedResult = result;
+
+ // attempt to de-serialize object
+ if (parser.createId != null) {
+ IRubyObject vKlassName = result.op_aref(context, parser.createId);
+ if (!vKlassName.isNil()) {
+ // might throw ArgumentError, we let it propagate
+ IRubyObject klass = parser.info.jsonModule.
+ callMethod(context, "deep_const_get", vKlassName);
+ if (klass.respondsTo("json_creatable?") &&
+ klass.callMethod(context, "json_creatable?").isTrue()) {
+
+ returnedResult = klass.callMethod(context, "json_create", result);
+ }
+ }
+ }
+ return new ParserResult(returnedResult, p + 1);
+ }
+
+ %%{
+ machine JSON;
+ include JSON_common;
+
+ write data;
+
+ action parse_object {
+ currentNesting = 1;
+ ParserResult res = parseObject(fpc, pe);
+ if (res == null) {
+ fhold;
+ fbreak;
+ } else {
+ result = res.result;
+ fexec res.p;
+ }
+ }
+
+ action parse_array {
+ currentNesting = 1;
+ ParserResult res = parseArray(fpc, pe);
+ if (res == null) {
+ fhold;
+ fbreak;
+ } else {
+ result = res.result;
+ fexec res.p;
+ }
+ }
+
+ main := ignore*
+ ( begin_object >parse_object
+ | begin_array >parse_array )
+ ignore*;
+ }%%
+
+ public IRubyObject parse() {
+ int cs = EVIL;
+ int p, pe;
+ IRubyObject result = null;
+
+ %% write init;
+ p = byteList.begin();
+ pe = p + byteList.length();
+ %% write exec;
+
+ if (cs >= JSON_first_final && p == pe) {
+ return result;
+ } else {
+ throw unexpectedToken(p, pe);
+ }
+ }
+
+ /**
+ * Returns a subsequence of the source ByteList, based on source
+ * array byte offsets (i.e., the ByteList's own begin offset is not
+ * automatically added).
+ * @param start
+ * @param end
+ */
+ private ByteList absSubSequence(int absStart, int absEnd) {
+ int offset = byteList.begin();
+ return (ByteList)byteList.subSequence(absStart - offset,
+ absEnd - offset);
+ }
+
+ /**
+ * Retrieves a constant directly descended from the <code>JSON</code> module.
+ * @param name The constant name
+ */
+ private IRubyObject getConstant(String name) {
+ return parser.info.jsonModule.getConstant(name);
+ }
+
+ private RaiseException newException(String className, String message) {
+ return Utils.newException(context, className, message);
+ }
+
+ private RaiseException newException(String className, RubyString message) {
+ return Utils.newException(context, className, message);
+ }
+
+ private RaiseException newException(String className,
+ String messageBegin, ByteList messageEnd) {
+ return newException(className,
+ getRuntime().newString(messageBegin).cat(messageEnd));
+ }
+ }
+}
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