Implement rust xml parser

Author: tmolitor-stud-tu

Monal/Classes/HelperTools.m

@@ -2924,12 +2924,9 @@ +(NSNumber*) dateToNSNumberSeconds:(NSDate*) date
     if(xmlString == nil)
         return nil;
     DDLogVerbose(@"Parsing XML string produced by rust sdp parser(withInitiator=%@): %@", bool2str(initiator), xmlString);
-    NSXMLParser* xmlParser = [[NSXMLParser alloc] initWithData:[xmlString dataUsingEncoding:NSUTF8StringEncoding]];
-    [xmlParser setShouldProcessNamespaces:YES];
-    [xmlParser setShouldReportNamespacePrefixes:YES];       //for debugging only
-    [xmlParser setShouldResolveExternalEntities:NO];
-    [xmlParser setDelegate:delegate];
-    [xmlParser parse];     //blocking operation
+    XmlParserBridge* xmlParser = [[XmlParserBridge alloc] initWith:delegate];
+    NSData* xmlData = [xmlString dataUsingEncoding:NSUTF8StringEncoding];
+    [xmlParser feedData:xmlData.bytes withLength:xmlData.length];     //blocking operation
     return retval;
 }
 

Monal/Classes/MLBasePaser.h

@@ -10,21 +10,27 @@
 #import <monalxmpp/MLXMLNode.h>
 
 //stanzas
-#import "XMPPIQ.h"
+#import <monalxmpp/XMPPIQ.h>
 #import <monalxmpp/XMPPPresence.h>
-#import "XMPPMessage.h"
+#import <monalxmpp/XMPPMessage.h>
 #import <monalxmpp/XMPPDataForm.h>
 
 
 NS_ASSUME_NONNULL_BEGIN
 
 typedef void (^stanza_completion_t)(MLXMLNode* _Nullable parsedStanza);
 
-@interface MLBasePaser : NSObject <NSXMLParserDelegate>
+@interface MLBasePaser : NSObject
 
 -(id) initWithCompletion:(stanza_completion_t) completion;
 -(void) reset;
 
+-(void) parserDidStartDocument:(NSString*) xmlVersion;
+-(void) parserDidStartElement:(NSString*) elementName namespaceURI:(NSString*) namespaceURI attributes:(NSDictionary*) attributeDict;
+-(void) parserFoundCharacters:(NSString*) string;
+-(void) parserDidEndInnermostElement;
+-(void) parserErrorOccurred:(NSString*) parseError;
+
 @end
 
 NS_ASSUME_NONNULL_END

Monal/Classes/MLBasePaser.m

@@ -9,9 +9,8 @@
 #import <monalxmpp/MLConstants.h>
 #import "MLBasePaser.h"
 
-//#define DebugParser(...)    DDLogDebug(__VA_ARGS__)
+// #define DebugParser(...)    DDLogDebug(__VA_ARGS__)
 #define DebugParser(...)
-
 @interface MLXMLNode()
 @property (atomic, readwrite) MLXMLNode* parent;
 -(MLXMLNode*) addChildNodeWithoutCopy:(MLXMLNode*) child;
@@ -23,7 +22,6 @@ @interface MLBasePaser ()
     //(the parent references of the MLXMLNodes are weak and don't hold the parents alive)
     NSMutableArray* _currentStack;
     stanza_completion_t _completion;
-    NSMutableArray* _namespacePrefixes;
 }
 @end
 
@@ -33,6 +31,7 @@ -(id) initWithCompletion:(stanza_completion_t) completion
 {
     self = [super init];
     _completion = completion;
+    [self reset];
     return self;
 }
 
@@ -41,26 +40,15 @@ -(void) reset
     _currentStack = [NSMutableArray new];
 }
 
--(void) parserDidStartDocument:(NSXMLParser*) parser
-{
-    DDLogInfo(@"Document start");
-    [self reset];
-}
-
--(void) parser:(NSXMLParser*) parser didStartMappingPrefix:(NSString*) prefix toURI:(NSString*) namespaceURI
-{
-    DebugParser(@"Got new namespace prefix mapping for '%@' to '%@'...", prefix, namespaceURI);
-}
-
--(void) parser:(NSXMLParser*) parser didEndMappingPrefix:(NSString*) prefix
+-(void) parserDidStartDocument:(NSString*) xmlVersion
 {
-    DebugParser(@"Namespace prefix '%@' now out of scope again...", prefix);
+    DDLogDebug(@"Document start, xml version: %@", xmlVersion);
 }
 
--(void) parser:(NSXMLParser*) parser didStartElement:(NSString*) elementName namespaceURI:(NSString*) namespaceURI qualifiedName:(NSString*) qName attributes:(NSDictionary*) attributeDict
+-(void) parserDidStartElement:(NSString*) elementName namespaceURI:(NSString*) namespaceURI attributes:(NSDictionary*) attributeDict
 {
     NSInteger depth = [_currentStack count] + 1;        //this makes the depth in here equal to the depth in didEndElement:
-    DebugParser(@"Started element: %@ :: %@ (%@) depth %ld", elementName, namespaceURI, qName, depth);
+    DebugParser(@"Started element: %@ :: %@ depth %ld", elementName, namespaceURI, depth);
 
     //use appropriate MLXMLNode child classes for iq, message and presence stanzas
     MLXMLNode* newNode;
@@ -77,28 +65,30 @@ -(void) parser:(NSXMLParser*) parser didStartElement:(NSString*) elementName nam
     newNode = [newNode initWithElement:elementName andNamespace:namespaceURI withAttributes:attributeDict andChildren:@[] andData:nil];
 
     DebugParser(@"Current stack: %@", _currentStack);
+    DebugParser(@"New node: %@", newNode);
     //add new node to tree (each node needs a prototype MLXMLNode element and a mutable string to hold its future
     //char data added to the MLXMLNode when the xml element is closed
     newNode.parent = [_currentStack lastObject][@"node"];
     [_currentStack addObject:@{@"node": newNode, @"charData": [NSMutableString new]}];
+    DebugParser(@"New stack: %@", _currentStack);
 }
 
--(void) parser:(NSXMLParser*) parser foundCharacters:(NSString*) string
+-(void) parserFoundCharacters:(NSString*) string
 {
     DebugParser(@"Got new xml character data: '%@'", string);
     NSInteger depth = [_currentStack count];
     if(depth == 0)
     {
         DDLogError(@"Got xml character data outside of any element!");
-        [self fakeStreamError];
+        [self fakeStreamErrorWithMessage:@"Got xml character data outside of any element!"];
         return;
     }
 
     [[_currentStack lastObject][@"charData"] appendString:string];
     DebugParser(@"_currentCharData is now: '%@'", [_currentStack lastObject][@"charData"]);
 }
 
--(void) parser:(NSXMLParser*) parser didEndElement:(NSString*) elementName namespaceURI:(NSString*) namespaceURI qualifiedName:(NSString*) qName
+-(void) parserDidEndInnermostElement
 {
     NSInteger depth = [_currentStack count];
     NSDictionary* topmostStackElement = [_currentStack lastObject];
@@ -107,7 +97,7 @@ -(void) parser:(NSXMLParser*) parser didEndElement:(NSString*) elementName names
     if([topmostStackElement[@"charData"] length])
         currentNode.data = [topmostStackElement[@"charData"] copy];
 
-    DebugParser(@"Ended element: %@ :: %@ (%@) depth %ld", elementName, namespaceURI, qName, depth);
+    DebugParser(@"Ended element: %@ depth %ld", currentNode.element, depth);
 
     MLXMLNode* parent = currentNode.parent;
     if(parent)
@@ -126,31 +116,19 @@ -(void) parser:(NSXMLParser*) parser didEndElement:(NSString*) elementName names
         _completion(currentNode);
 }
 
--(void) parserDidEndDocument:(NSXMLParser*) parser
-{
-    DDLogInfo(@"Document end");
-}
-
--(void) parser:(NSXMLParser*) parser foundIgnorableWhitespace:(NSString*) whitespaceString
+-(void) parserErrorOccurred:(NSString*) parseError
 {
-    DebugParser(@"Found ignorable whitespace: '%@'", whitespaceString);
+    [self fakeStreamErrorWithMessage:parseError];
 }
 
--(void) parser:(NSXMLParser*) parser parseErrorOccurred:(NSError*) parseError
-{
-    DDLogError(@"XML parse error occurred: line: %ld , col: %ld desc: %@ ",(long)[parser lineNumber],
-               (long)[parser columnNumber], [parseError localizedDescription]);
-    [self fakeStreamError];
-}
-
--(void) fakeStreamError
+-(void) fakeStreamErrorWithMessage:(NSString*) message
 {
     //fake stream error and let xmpp.m handle it
     _completion([[MLXMLNode alloc] initWithElement:@"error" andNamespace:@"http://etherx.jabber.org/streams" withAttributes:@{} andChildren:@[
         [[MLXMLNode alloc] initWithElement:@"bad-format" andNamespace:@"urn:ietf:params:xml:ns:xmpp-streams" withAttributes:@{} andChildren:@[
-            [[MLXMLNode alloc] initWithElement:@"text" andNamespace:@"urn:ietf:params:xml:ns:xmpp-streams" withAttributes:@{} andChildren:@[] andData:@"Could not parse XML coming from server"]
+            [[MLXMLNode alloc] initWithElement:@"text" andNamespace:@"urn:ietf:params:xml:ns:xmpp-streams" withAttributes:@{} andChildren:@[] andData:[NSString stringWithFormat:@"Could not parse XML coming from server: %@", message]]
         ] andData:nil]
     ] andData:nil]);
 }
 
-@end
+@end

Monal/Classes/SwiftHelpers.swift

@@ -466,8 +466,6 @@ fileprivate extension RustVec {
     }
 }
 
-extension RustString: @retroactive Error {}
-
 @objcMembers
 public class JingleSDPBridge : NSObject {
     @objc(getJingleStringForSDPString:withInitiator:)
@@ -506,3 +504,55 @@ public class HtmlParserBridge : NSObject {
         return self.document.select(selector, attribute).intoArray().map { $0.toString() }
     }
 }
+
+@objcMembers
+public class XmlParserBridge : NSObject {
+    var wrapped: MonalXmlStreamParserWrapper
+    var delegate: MLBasePaser
+    
+    public init(with delegate: MLBasePaser) {
+        //never buffer more than 8192 bytes inside the rust parser and limit maximum
+        //token length (attribute value, attribute name, element name) to 1024
+        self.wrapped = MonalXmlStreamParserWrapper(8192, 1024)
+        self.delegate = delegate
+    }
+    
+    @objc(feedData:withLength:)
+    public func feed(data chunk: UnsafePointer<UInt8>, length size: Int) {
+        do {
+            //this is zero-copy
+            self.wrapped.feed(UnsafeBufferPointer(start: chunk, count: size))
+            var notDoneYet = true
+            while notDoneYet {
+                switch try self.wrapped.poll() {
+                    case .XmlDeclaration(let version):
+                        self.delegate.parserDidStartDocument(version.toString())
+                    case .Start(let element):
+                        let keys: [String] = element.attr_keys!.intoArray().map { $0.toString() }
+                        let values: [String] = element.attr_values!.intoArray().map { $0.toString() }
+                        MLAssert(keys.count == values.count, "Atrribute vectors coming from rust should have the same sizes!", [
+                            "keys": keys as NSArray,
+                            "values": values as NSArray,
+                        ])
+                        var attributes: [String:String] = [:]
+                        for i in 0..<keys.count {
+                            attributes[keys[i]] = values[i]
+                        }
+                        self.delegate.parserDidStartElement(element.name.toString(), namespaceURI:element.ns.toString(), attributes:attributes)
+                    case .End:
+                        self.delegate.parserDidEndInnermostElement()
+                    case .Text(let text):
+                        self.delegate.parserFoundCharacters(text.toString())
+                    case .NeedMoreData:
+                        notDoneYet = false
+                }
+            }
+        } catch let err as RustString {
+            DDLogError("XML parser returned error: \(err.toString())")
+            self.delegate.parserErrorOccurred(err.toString())
+        } catch let err {
+            DDLogError("XML parser returned UNEXPECTED error: \(String(describing:err))")
+            unreachable("xml parser should never return non-string errors!")
+        }
+    }
+}