From 4d39507183e0ace2d73f04817a398e858b66b677 Mon Sep 17 00:00:00 2001
From: Jan Breuer <jan.breuer@jaybee.cz>
Date: 周五, 22 3月 2013 01:40:22 +0800
Subject: [PATCH] Update lexer, start of implementing parser

---
 libscpi/src/utils.c |  328 ++++++++++++++++++++++++++++++++++--------------------
 1 files changed, 206 insertions(+), 122 deletions(-)

diff --git a/libscpi/src/utils.c b/libscpi/src/utils.c
index 9f9e2e7..8880636 100644
--- a/libscpi/src/utils.c
+++ b/libscpi/src/utils.c
@@ -147,152 +147,214 @@
         return FALSE;
     }
 
-    if (strncasecmp(str1, str2, len2) == 0) {
+    if (SCPI_strncasecmp(str1, str2, len2) == 0) {
         return TRUE;
     }
 
     return FALSE;
 }
 
-bool_t locateText(const char * str1, size_t len1, char ** str2, size_t * len2) {
+enum _locate_text_states {
+    STATE_FIRST_WHITESPACE,
+    STATE_TEXT_QUOTED,
+    STATE_TEXT,
+    STATE_LAST_WHITESPACE,
+    STATE_COMMA,
+    STATE_ERROR
+};
+typedef enum _locate_text_states locate_text_states;
+
+struct _locate_text_nfa {
+    locate_text_states state;
+    int32_t startIdx;
+    int32_t stopIdx;
     size_t i;
-    int quot = 0;
-    int32_t strStart = -1;
-    int32_t strStop = -1;
-    int valid = 0;
+};
+typedef struct _locate_text_nfa locate_text_nfa;
 
-
-    for (i = 0; i < len1; i++) {
-        if ((strStart < 0) && isspace(str1[i])) {
-            continue;
-        }
-
-        if ((strStart < 0) && !quot && (str1[i] == '"')) {
-            quot = 1;
-            continue;
-        }
-
-        if (strStart < 0) {
-            strStart = i;
-        }
-
-        if ((strStop < 0) && quot && (str1[i] == '"')) {
-            strStop = i;
-            valid = 1;
-            continue;
-        }
-
-        if ((strStop >= 0) && quot && (str1[i] == ',')) {
-            break;
-        }
-
-        if ((strStop >= 0) && quot && !isspace(str1[i])) {
-            valid = 0;
-        }
-
-        if (!quot && !isspace(str1[i]) && (str1[i] != ',')) {
-            strStop = i;
-        }
-
-        if (isspace(str1[i])) {
-            continue;
-        }
-
-        if ((strStop >= 0) && (str1[i] == ',')) {
-            valid = 1;
-            break;
-        }
-    }
-
-    if ((i == len1) && !quot) {
-        valid = 1;
-        if (strStop < 0) {
-            strStop = i;
-        } else {
-            strStop++;
-        }
-        if (strStart < 0) {
-            strStart = i;
-        }
-    } else if (!quot) {
-        strStop++;
-    }
-
-
-    if (valid) {
-        if (str2) {
-            *str2 = (char *) &str1[strStart];
-        }
-
-        if (len2) {
-            *len2 = strStop - strStart;
-        }
-    }
-
-    return valid;
+/**
+ * Test locate text state, if it is correct final state
+ */
+static bool_t isFinalState(locate_text_states state) {
+    return (
+        ((state) == STATE_COMMA)
+        || ((state) == STATE_LAST_WHITESPACE)
+        || ((state) == STATE_TEXT) ||
+        ((state) == STATE_FIRST_WHITESPACE)
+    );
 }
 
-bool_t locateStr(const char * str1, size_t len1, char ** str2, size_t * len2) {
-    size_t i;
-    int32_t strStart = -1;
-    int32_t strStop = -1;
-    int valid = 0;
-
-
-    for (i = 0; i < len1; i++) {
-        if ((strStart < 0) && isspace(str1[i])) {
-            continue;
-        }
-
-        if (strStart < 0) {
-            strStart = i;
-        }
-
-        if (!isspace(str1[i]) && (str1[i] != ',')) {
-            strStop = i;
-        }
-
-        if (isspace(str1[i])) {
-            continue;
-        }
-
-        if (str1[i] == ',') {
-            valid = 1;
-
-            if (strStop < 0) {
-                strStop = i;
+/**
+ * Perform locateText automaton to search string pattern
+ * @param nfa stores automaton state
+ * @param c current char processed
+ */
+static bool_t locateTextAutomaton(locate_text_nfa * nfa, unsigned char c) {
+    switch(nfa->state) {
+        /* first state locating only white spaces */
+        case STATE_FIRST_WHITESPACE:
+            if(isspace(c)) {
+                nfa->startIdx = nfa->stopIdx = nfa->i + 1;
+            } else if (c == ',') {
+                nfa->state = STATE_COMMA;
+            } else if (c == '"') {
+                nfa->startIdx = nfa->i + 1;
+                nfa->state = STATE_TEXT_QUOTED;
+            } else {
+                nfa->startIdx = nfa->i;
+                nfa->stopIdx = nfa->i + 1;
+                nfa->state = STATE_TEXT;
             }
             break;
-        }
+        /* state locating any text inside "" */
+        case STATE_TEXT_QUOTED:
+            if(c == '"') {
+                nfa->state = STATE_LAST_WHITESPACE;
+                nfa->stopIdx = nfa->i;
+            }
+            break;
+        /* locate text ignoring quotes */
+        case STATE_TEXT:
+            if (c == ',') {
+                nfa->state = STATE_COMMA;
+            } else if (!isspace(c)) {
+                nfa->stopIdx = nfa->i + 1;
+            }
+            break;
+        /* locating text after last quote */
+        case STATE_LAST_WHITESPACE:
+            if (c == ',') {
+                nfa->state = STATE_COMMA;
+            } else if (!isspace(c)) {
+                nfa->state = STATE_ERROR;
+            }
+            break;
+
+        default:
+            break;
     }
 
-    if (i == len1) {
-        valid = 1;
-        if (strStop < 0) {
-            strStop = i;
-        } else {
-            strStop++;
-        }
-        if (strStart < 0) {
-            strStart = i;
-        }
+    /* if it is terminating state, break from for loop */
+    if ((nfa->state == STATE_COMMA) || (nfa->state == STATE_ERROR)) {
+        return FALSE;
     } else {
-        strStop++;
+        return TRUE;
+    }
+}
+
+/**
+ * Locate text in string. Text is separated by two ""
+ *   example: "text", next parameter
+ *   regexp: ^[ \t\r\n]*"([^"]*)"[ \t\r\n]*,?
+ *   regexp: ^[ \t\r\n]*([^,]*)[ \t\r\n]*,?
+ * @param str1 string to be searched
+ * @param len1 length of string
+ * @param str2 result
+ * @param len2 length of result
+ * @return string str1 contains text and str2 was set
+ */
+bool_t locateText(const char * str1, size_t len1, const char ** str2, size_t * len2) {
+    locate_text_nfa nfa;
+    nfa.state = STATE_FIRST_WHITESPACE;
+    nfa.startIdx = 0;
+    nfa.stopIdx = 0;
+
+    for (nfa.i = 0; nfa.i < len1; nfa.i++) {
+        if(FALSE == locateTextAutomaton(&nfa, str1[nfa.i])) {
+            break;
+        }
     }
 
+    if (isFinalState(nfa.state)) {
 
-    if (valid) {
         if (str2) {
-            *str2 = (char *) &str1[strStart];
+            *str2 = &str1[nfa.startIdx];
         }
 
         if (len2) {
-            *len2 = strStop - strStart;
+            *len2 = nfa.stopIdx - nfa.startIdx;
+        }
+        return TRUE;
+    }
+    return FALSE;
+}
+
+/**
+ * Perform locateStr automaton to search string pattern
+ * @param nfa stores automaton state
+ * @param c current char processed
+ */
+static bool_t locateStrAutomaton(locate_text_nfa * nfa, unsigned char c) {
+    switch(nfa->state) {
+        /* first state locating only white spaces */
+        case STATE_FIRST_WHITESPACE:
+            if(isspace(c)) {
+                nfa->startIdx = nfa->stopIdx = nfa->i + 1;
+            } else if (c == ',') {
+                nfa->state = STATE_COMMA;
+            } else {
+                nfa->startIdx = nfa->i;
+                nfa->stopIdx = nfa->i + 1;
+                nfa->state = STATE_TEXT;
+            }
+            break;
+        /* locate text ignoring quotes */
+        case STATE_TEXT:
+            if (c == ',') {
+                nfa->state = STATE_COMMA;
+            } else if (!isspace(c)) {
+                nfa->stopIdx = nfa->i + 1;
+            }
+            break;
+
+        default:
+            break;            
+    }
+
+    /* if it is terminating state, break from for loop */
+    if ((nfa->state == STATE_COMMA) || (nfa->state == STATE_ERROR)) {
+        return FALSE;
+    } else {
+        return TRUE;
+    }
+}
+
+/**
+ * Locate string in string.
+ *   regexp: ^[ \t\r\n]*([^,]*)[ \t\r\n]*,?
+ * @param str1 string to be searched
+ * @param len1 length of string
+ * @param str2 result
+ * @param len2 length of result
+ * @return string str1 contains text and str2 was set
+ */
+bool_t locateStr(const char * str1, size_t len1, const char ** str2, size_t * len2) {
+    locate_text_nfa nfa;
+    nfa.state = STATE_FIRST_WHITESPACE;
+    nfa.startIdx = 0;
+    nfa.stopIdx = 0;
+
+
+    for (nfa.i = 0; nfa.i < len1; nfa.i++) {
+        if(FALSE == locateStrAutomaton(&nfa, str1[nfa.i])) {
+            break;
         }
     }
 
-    return valid;
+    if (isFinalState(nfa.state)) {
+
+        if (str2) {
+            *str2 = &str1[nfa.startIdx];
+        }
+
+        if (len2) {
+            *len2 = nfa.stopIdx - nfa.startIdx;
+        }
+        return TRUE;
+    }
+    return FALSE;
 }
+
 
 /**
  * Count white spaces from the beggining
@@ -303,7 +365,7 @@
 size_t skipWhitespace(const char * cmd, size_t len) {
     size_t i;
     for (i = 0; i < len; i++) {
-        if (!isspace(cmd[i])) {
+        if (!isspace((unsigned char)cmd[i])) {
             return i;
         }
     }
@@ -321,7 +383,7 @@
 size_t patternSeparatorShortPos(const char * pattern, size_t len) {
     size_t i;
     for (i = 0; (i < len) && pattern[i]; i++) {
-        if (islower(pattern[i])) {
+        if (islower((unsigned char)pattern[i])) {
             return i;
         }
     }
@@ -341,3 +403,25 @@
     return compareStr(pattern, pattern_len, str, str_len) ||
             compareStr(pattern, pattern_sep_pos_short, str, str_len);
 }
+
+
+#if !HAVE_STRNLEN
+/* use FreeBSD strnlen */
+
+/*-
+ * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
+ * All rights reserved.
+ */
+size_t
+BSD_strnlen(const char *s, size_t maxlen)
+{
+	size_t len;
+	
+	for (len = 0; len < maxlen; len++, s++) {
+		if (!*s)
+			break;
+	}
+	return (len);
+}
+#endif
+

--
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