json: Have lexer call streamer directly

json_lexer_init() takes the function to process a token as an
argument.  It's always json_message_process_token().  Makes the code
harder to understand for no actual gain.  Drop the indirection.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-34-armbru@redhat.com>

include/qapi/qmp/json-lexer.h

@@ -32,20 +32,13 @@ typedef enum json_token_type {
     JSON_ERROR,
 } JSONTokenType;
 
-typedef struct JSONLexer JSONLexer;
+typedef struct JSONLexer {
-
-typedef void (JSONLexerEmitter)(JSONLexer *, GString *,
-                                JSONTokenType, int x, int y);
-
-struct JSONLexer
-{
-    JSONLexerEmitter *emit;
     int state;
     GString *token;
     int x, y;
-};
+} JSONLexer;
 
-void json_lexer_init(JSONLexer *lexer, JSONLexerEmitter func);
+void json_lexer_init(JSONLexer *lexer);
 
 void json_lexer_feed(JSONLexer *lexer, const char *buffer, size_t size);
 

include/qapi/qmp/json-streamer.h

@@ -33,6 +33,9 @@ typedef struct JSONMessageParser
     uint64_t token_size;
 } JSONMessageParser;
 
+void json_message_process_token(JSONLexer *lexer, GString *input,
+                                JSONTokenType type, int x, int y);
+
 void json_message_parser_init(JSONMessageParser *parser,
                               void (*func)(JSONMessageParser *, GQueue *));
 

qobject/json-lexer.c

@@ -14,6 +14,7 @@
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "qapi/qmp/json-lexer.h"
+#include "qapi/qmp/json-streamer.h"
 
 #define MAX_TOKEN_SIZE (64ULL << 20)
 
@@ -278,9 +279,8 @@ static const uint8_t json_lexer[][256] =  {
     },
 };
 
-void json_lexer_init(JSONLexer *lexer, JSONLexerEmitter func)
+void json_lexer_init(JSONLexer *lexer)
 {
-    lexer->emit = func;
     lexer->state = IN_START;
     lexer->token = g_string_sized_new(3);
     lexer->x = lexer->y = 0;
@@ -316,7 +316,8 @@ static void json_lexer_feed_char(JSONLexer *lexer, char ch, bool flush)
         case JSON_FLOAT:
         case JSON_KEYWORD:
         case JSON_STRING:
-            lexer->emit(lexer, lexer->token, new_state, lexer->x, lexer->y);
+            json_message_process_token(lexer, lexer->token, new_state,
+                                       lexer->x, lexer->y);
             /* fall through */
         case JSON_SKIP:
             g_string_truncate(lexer->token, 0);
@@ -336,7 +337,8 @@ static void json_lexer_feed_char(JSONLexer *lexer, char ch, bool flush)
              * never a valid ASCII/UTF-8 sequence, so this should reliably
              * induce an error/flush state.
              */
-            lexer->emit(lexer, lexer->token, JSON_ERROR, lexer->x, lexer->y);
+            json_message_process_token(lexer, lexer->token, JSON_ERROR,
+                                       lexer->x, lexer->y);
             g_string_truncate(lexer->token, 0);
             new_state = IN_START;
             lexer->state = new_state;
@@ -351,7 +353,8 @@ static void json_lexer_feed_char(JSONLexer *lexer, char ch, bool flush)
      * this is a security consideration.
      */
     if (lexer->token->len > MAX_TOKEN_SIZE) {
-        lexer->emit(lexer, lexer->token, lexer->state, lexer->x, lexer->y);
+        json_message_process_token(lexer, lexer->token, lexer->state,
+                                   lexer->x, lexer->y);
         g_string_truncate(lexer->token, 0);
         lexer->state = IN_START;
     }

qobject/json-streamer.c

@@ -34,8 +34,8 @@ static void json_message_free_tokens(JSONMessageParser *parser)
     }
 }
 
-static void json_message_process_token(JSONLexer *lexer, GString *input,
+void json_message_process_token(JSONLexer *lexer, GString *input,
-                                       JSONTokenType type, int x, int y)
+                                JSONTokenType type, int x, int y)
 {
     JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
     JSONToken *token;
@@ -115,7 +115,7 @@ void json_message_parser_init(JSONMessageParser *parser,
     parser->tokens = g_queue_new();
     parser->token_size = 0;
 
-    json_lexer_init(&parser->lexer, json_message_process_token);
+    json_lexer_init(&parser->lexer);
 }
 
 void json_message_parser_feed(JSONMessageParser *parser,