Diff: jsmn.c

Revision:

0:625bfa0ff591

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jsmn.c	Wed Jan 22 15:21:09 2014 +0000
@@ -0,0 +1,254 @@
+#include <stdlib.h>
+
+#include "jsmn.h"
+
+/**
+ * Allocates a fresh unused token from the token pull.
+ */
+static jsmntok_t *jsmn_alloc_token(jsmn_parser *parser, 
+        jsmntok_t *tokens, size_t num_tokens) {
+    jsmntok_t *tok;
+    if (parser->toknext >= num_tokens) {
+        return NULL;
+    }
+    tok = &tokens[parser->toknext++];
+    tok->start = tok->end = -1;
+    tok->size = 0;
+#ifdef JSMN_PARENT_LINKS
+    tok->parent = -1;
+#endif
+    return tok;
+}
+
+/**
+ * Fills token type and boundaries.
+ */
+static void jsmn_fill_token(jsmntok_t *token, jsmntype_t type, 
+                            int start, int end) {
+    token->type = type;
+    token->start = start;
+    token->end = end;
+    token->size = 0;
+}
+
+/**
+ * Fills next available token with JSON primitive.
+ */
+static jsmnerr_t jsmn_parse_primitive(jsmn_parser *parser, char *js,
+        jsmntok_t *tokens, size_t num_tokens) {
+    jsmntok_t *token;
+    int start;
+
+    start = parser->pos;
+
+    for (; js[parser->pos] != '\0'; parser->pos++) {
+        switch (js[parser->pos]) {
+#ifndef JSMN_STRICT
+            /* In strict mode primitive must be followed by "," or "}" or "]" */
+            case ':':
+#endif
+            case '\t' : case '\r' : case '\n' : case ' ' :
+            case ','  : case ']'  : case '}' :
+                goto found;
+        }
+        if (js[parser->pos] < 32 || js[parser->pos] >= 127) {
+            parser->pos = start;
+            return JSMN_ERROR_INVAL;
+        }
+    }
+#ifdef JSMN_STRICT
+    /* In strict mode primitive must be followed by a comma/object/array */
+    parser->pos = start;
+    return JSMN_ERROR_PART;
+#endif
+
+found:
+    token = jsmn_alloc_token(parser, tokens, num_tokens);
+    if (token == NULL) {
+        parser->pos = start;
+        return JSMN_ERROR_NOMEM;
+    }
+    jsmn_fill_token(token, JSMN_PRIMITIVE, start, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+    token->parent = parser->toksuper;
+#endif
+    parser->pos--;
+    return JSMN_SUCCESS;
+}
+
+/**
+ * Filsl next token with JSON string.
+ */
+static jsmnerr_t jsmn_parse_string(jsmn_parser *parser, const char *js,
+        jsmntok_t *tokens, size_t num_tokens) {
+    jsmntok_t *token;
+
+    int start = parser->pos;
+
+    parser->pos++;
+
+    /* Skip starting quote */
+    for (; js[parser->pos] != '\0'; parser->pos++) {
+        char c = js[parser->pos];
+
+        /* Quote: end of string */
+        if (c == '\"') {
+            token = jsmn_alloc_token(parser, tokens, num_tokens);
+            if (token == NULL) {
+                parser->pos = start;
+                return JSMN_ERROR_NOMEM;
+            }
+            jsmn_fill_token(token, JSMN_STRING, start+1, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+            token->parent = parser->toksuper;
+#endif
+            return JSMN_SUCCESS;
+        }
+
+        /* Backslash: Quoted symbol expected */
+        if (c == '\\') {
+            parser->pos++;
+            switch (js[parser->pos]) {
+                /* Allowed escaped symbols */
+                case '\"': case '/' : case '\\' : case 'b' :
+                case 'f' : case 'r' : case 'n'  : case 't' :
+                    break;
+                /* Allows escaped symbol \uXXXX */
+                case 'u':
+                    /* TODO */
+                    break;
+                /* Unexpected symbol */
+                default:
+                    parser->pos = start;
+                    return JSMN_ERROR_INVAL;
+            }
+        }
+    }
+    parser->pos = start;
+    return JSMN_ERROR_PART;
+}
+
+/**
+ * Parse JSON string and fill tokens.
+ */
+jsmnerr_t jsmn_parse(jsmn_parser *parser, char *js, jsmntok_t *tokens, 
+        unsigned int num_tokens) {
+    jsmnerr_t r;
+    int i;
+    jsmntok_t *token;
+
+    for (; js[parser->pos] != '\0'; parser->pos++) {
+        char c;
+        jsmntype_t type;
+
+        c = js[parser->pos];
+        switch (c) {
+            case '{': case '[':
+                token = jsmn_alloc_token(parser, tokens, num_tokens);
+                if (token == NULL)
+                    return JSMN_ERROR_NOMEM;
+                if (parser->toksuper != -1) {
+                    tokens[parser->toksuper].size++;
+#ifdef JSMN_PARENT_LINKS
+                    token->parent = parser->toksuper;
+#endif
+                }
+                token->type = (c == '{' ? JSMN_OBJECT : JSMN_ARRAY);
+                token->start = parser->pos;
+                parser->toksuper = parser->toknext - 1;
+                break;
+            case '}': case ']':
+                type = (c == '}' ? JSMN_OBJECT : JSMN_ARRAY);
+#ifdef JSMN_PARENT_LINKS
+                if (parser->toknext < 1) {
+                    return JSMN_ERROR_INVAL;
+                }
+                token = &tokens[parser->toknext - 1];
+                for (;;) {
+                    if (token->start != -1 && token->end == -1) {
+                        if (token->type != type) {
+                            return JSMN_ERROR_INVAL;
+                        }
+                        token->end = parser->pos + 1;
+                        parser->toksuper = token->parent;
+                        break;
+                    }
+                    if (token->parent == -1) {
+                        break;
+                    }
+                    token = &tokens[token->parent];
+                }
+#else
+                for (i = parser->toknext - 1; i >= 0; i--) {
+                    token = &tokens[i];
+                    if (token->start != -1 && token->end == -1) {
+                        if (token->type != type) {
+                            return JSMN_ERROR_INVAL;
+                        }
+                        parser->toksuper = -1;
+                        token->end = parser->pos + 1;
+                        break;
+                    }
+                }
+                /* Error if unmatched closing bracket */
+                if (i == -1) return JSMN_ERROR_INVAL;
+                for (; i >= 0; i--) {
+                    token = &tokens[i];
+                    if (token->start != -1 && token->end == -1) {
+                        parser->toksuper = i;
+                        break;
+                    }
+                }
+#endif
+                break;
+            case '\"':
+                r = jsmn_parse_string(parser, js, tokens, num_tokens);
+                if (r < 0) return r;
+                if (parser->toksuper != -1)
+                    tokens[parser->toksuper].size++;
+                break;
+            case '\t' : case '\r' : case '\n' : case ':' : case ',': case ' ': 
+                break;
+#ifdef JSMN_STRICT
+            /* In strict mode primitives are: numbers and booleans */
+            case '-': case '0': case '1' : case '2': case '3' : case '4':
+            case '5': case '6': case '7' : case '8': case '9':
+            case 't': case 'f': case 'n' :
+#else
+            /* In non-strict mode every unquoted value is a primitive */
+            default:
+#endif
+                r = jsmn_parse_primitive(parser, js, tokens, num_tokens);
+                if (r < 0) return r;
+                if (parser->toksuper != -1)
+                    tokens[parser->toksuper].size++;
+                break;
+
+#ifdef JSMN_STRICT
+            /* Unexpected char in strict mode */
+            default:
+                return JSMN_ERROR_INVAL;
+#endif
+
+        }
+    }
+
+    for (i = parser->toknext - 1; i >= 0; i--) {
+        /* Unmatched opened object or array */
+        if (tokens[i].start != -1 && tokens[i].end == -1) {
+            return JSMN_ERROR_PART;
+        }
+    }
+
+    return JSMN_SUCCESS;
+}
+
+/**
+ * Creates a new parser based over a given  buffer with an array of tokens 
+ * available.
+ */
+void jsmn_init(jsmn_parser *parser) {
+    parser->pos = 0;
+    parser->toknext = 0;
+    parser->toksuper = -1;
+}
\ No newline at end of file