replace buffer2array() with cstrtok() from mpd-ke

This modifies the string in place, and does not allocate any memory from
the heap.  This is considerably smaller than the function it replaces,
and will be instrumental in getting the commands/conf malloc reductions
done.

git-svn-id: https://svn.musicpd.org/mpd/trunk@4481 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/buffer2array.c

@@ -21,99 +21,43 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <ctype.h>
 
-int buffer2array(char *origBuffer, char ***array)
+int cstrtok(char *buffer, char *array[], const int max)
 {
-	int quotes = 0;
-	int count = 0;
-	int i;
-	int curr;
-	int *beginArray;
-	char *buffer = strdup(origBuffer);
-	int bufferLength = strlen(buffer);
-	char *markArray = malloc(sizeof(char) * (bufferLength + 1));
+	int i = 0;
+	char *c = buffer;
 
-	for (curr = 0; curr < bufferLength; curr++) {
-		if (!quotes && (buffer[curr] == ' ' || buffer[curr] == '\t')) {
-			markArray[curr] = '0';
-		} else if (buffer[curr] == '\"') {
-			if (curr > 0 && buffer[curr - 1] != '\\') {
-				quotes = quotes ? 0 : 1;
-				markArray[curr] = '0';
-			} else {
-				markArray[curr] = '1';
+	while (*c != '\0' && i < max) {
+		if (*c == '\"') {
+			int escape = 0;
+			array[i++] = ++c;
+			while (*c != '\0') {
+				if (*c == '\"') {
+					if (escape)
+						memmove(c - 1, c,
+							strlen(c) + 1);
+					else {
+						*(c++) = '\0';
+						break;
+					}
+				}
+				escape = (*(c++) != '\\') ? 0 : !escape;
 			}
 		} else {
-			markArray[curr] = '1';
-		}
-		if (markArray[curr] == '1') {
-			if (curr > 0) {
-				if (markArray[curr - 1] == '0') {
-					count++;
-				}
-			} else {
-				count++;
-			}
+			while (isspace(*c))
+				++c;
+			array[i++] = c++;
+			if (*c == '\0')
+				return i;
+			while (!isspace(*c) && *c != '\0')
+				++c;
 		}
+		if (*c == '\0')
+			return i;
+		*(c++) = '\0';
+		while (isspace(*c))
+			++c;
 	}
-	markArray[bufferLength] = '\0';
-
-	if (!count) {
-		free(buffer);
-		free(markArray);
-		return count;
-	}
-
-	beginArray = malloc(sizeof(int) * count);
-	(*array) = malloc(sizeof(char *) * count);
-
-	count = 0;
-
-	for (curr = 0; curr < bufferLength; curr++) {
-		if (markArray[curr] == '1') {
-			if (curr > 0) {
-				if (markArray[curr - 1] == '0') {
-					beginArray[count++] = curr;
-				}
-			} else {
-				beginArray[count++] = curr;
-			}
-		} else {
-			buffer[curr] = '\0';
-		}
-	}
-
-	for (i = 0; i < count; i++) {
-		int len = strlen(buffer + beginArray[i]) + 1;
-		int arrayCurr = 0;
-		(*array)[i] = malloc(sizeof(char) * len);
-		for (curr = beginArray[i]; buffer[curr] != '\0'; curr++) {
-			if (buffer[curr] == '\\') {
-				if (buffer[curr + 1] != '\0') {
-					curr++;
-				}
-			}
-			(*array)[i][arrayCurr++] = buffer[curr];
-		}
-		(*array)[i][arrayCurr] = '\0';
-	}
-
-	free(markArray);
-	free(beginArray);
-	free(buffer);
-
-	return count;
-}
-
-void freeArgArray(char **array, int argArrayLength)
-{
-	int i;
-
-	if (argArrayLength == 0)
-		return;
-
-	for (i = 0; i < argArrayLength; i++) {
-		free(array[i]);
-	}
-	free(array);
+	return i;
 }

src/buffer2array.h

@@ -21,8 +21,12 @@
 
 #include "../config.h"
 
-int buffer2array(char *buffer, char ***array);
-
-void freeArgArray(char **array, int argArrayLength);
+/* tokenizes up to max elements in buffer (a null-terminated string) and
+ * stores the result in array (which must be capable of holding up to
+ * max elements).  Tokenization is based on C string quoting rules.
+ * The arguments buffer and array are modified.
+ * Returns the number of elements tokenized.
+ */
+int cstrtok(char *buffer, char *array[], const int max);
 
 #endif

src/command.c

@@ -104,6 +104,11 @@
 #define COMMAND_STATUS_AUDIO		"audio"
 #define COMMAND_STATUS_UPDATING_DB	"updating_db"
 
+/* the most we ever use is argv[2], so argv[] has (at most)
+ * 3 usable elements. This means we tokenize up to 4 elements to
+ * detect errors clients may send us */
+#define COMMAND_ARGV_MAX	4
+
 typedef struct _CommandEntry CommandEntry;
 
 typedef int (*CommandHandlerFunction) (FILE *, int *, int, char **);
@@ -1138,16 +1143,14 @@ static CommandEntry *getCommandEntryAndCheckArgcAndPermission(FILE * fp,
 static CommandEntry *getCommandEntryFromString(char *string, int *permission)
 {
 	CommandEntry *cmd = NULL;
-	char **argv;
-	int argc = buffer2array(string, &argv);
+	char *argv[COMMAND_ARGV_MAX] = { 0 };
+	int argc = cstrtok(string, argv, COMMAND_ARGV_MAX);
 
 	if (0 == argc)
 		return NULL;
 
 	cmd = getCommandEntryAndCheckArgcAndPermission(NULL, permission,
-						       argc,
-						       argv);
-	freeArgArray(argv, argc);
+						       argc, argv);
 
 	return cmd;
 }
@@ -1156,29 +1159,25 @@ static int processCommandInternal(FILE * fp, int *permission,
 				  char *commandString, ListNode * commandNode)
 {
 	int argc;
-	char **argv;
+	char *argv[COMMAND_ARGV_MAX] = { 0 };
 	CommandEntry *cmd;
 	int ret = -1;
 
-	argc = buffer2array(commandString, &argv);
+	argc = cstrtok(commandString, argv, COMMAND_ARGV_MAX);
 
 	if (argc == 0)
 		return 0;
 
 	if ((cmd = getCommandEntryAndCheckArgcAndPermission(fp, permission,
-							    argc,
-							    argv))) {
+							    argc, argv))) {
 		if (NULL == commandNode || NULL == cmd->listHandler) {
-			ret = cmd->handler(fp, permission, argc,
-					   argv);
+			ret = cmd->handler(fp, permission, argc, argv);
 		} else {
-			ret = cmd->listHandler(fp, permission, argc,
-					       argv, commandNode, cmd);
+			ret = cmd->listHandler(fp, permission, argc, argv,
+			                       commandNode, cmd);
 		}
 	}
 
-	freeArgArray(argv, argc);
-
 	current_command = NULL;
 
 	return ret;

src/conf.c

@@ -41,6 +41,7 @@
 
 #define CONF_REPEATABLE_MASK	0x01
 #define CONF_BLOCK_MASK		0x02
+#define CONF_LINE_TOKEN_MAX	3
 
 typedef struct _configEntry {
 	unsigned char mask;
@@ -193,15 +194,16 @@ static ConfigParam *readConfigBlock(FILE * fp, int *count, char *string)
 {
 	ConfigParam *ret = newConfigParam(NULL, *count);
 
-	char **array;
 	int i;
 	int numberOfArgs;
 	int argsMinusComment;
 
 	while (myFgets(string, MAX_STRING_SIZE, fp)) {
+		char *array[CONF_LINE_TOKEN_MAX] = { 0 };
+
 		(*count)++;
 
-		numberOfArgs = buffer2array(string, &array);
+		numberOfArgs = cstrtok(string, array, CONF_LINE_TOKEN_MAX);
 
 		for (i = 0; i < numberOfArgs; i++) {
 			if (array[i][0] == CONF_COMMENT)
@@ -211,13 +213,11 @@ static ConfigParam *readConfigBlock(FILE * fp, int *count, char *string)
 		argsMinusComment = i;
 
 		if (0 == argsMinusComment) {
-			freeArgArray(array, numberOfArgs);
 			continue;
 		}
 
 		if (1 == argsMinusComment &&
 		    0 == strcmp(array[0], CONF_BLOCK_END)) {
-			freeArgArray(array, numberOfArgs);
 			break;
 		}
 
@@ -238,8 +238,6 @@ static ConfigParam *readConfigBlock(FILE * fp, int *count, char *string)
 		}
 
 		addBlockParam(ret, array[0], array[1], *count);
-
-		freeArgArray(array, numberOfArgs);
 	}
 
 	return ret;
@@ -249,7 +247,6 @@ void readConf(char *file)
 {
 	FILE *fp;
 	char string[MAX_STRING_SIZE + 1];
-	char **array;
 	int i;
 	int numberOfArgs;
 	int argsMinusComment;
@@ -265,9 +262,10 @@ void readConf(char *file)
 	}
 
 	while (myFgets(string, MAX_STRING_SIZE, fp)) {
+		char *array[CONF_LINE_TOKEN_MAX] = { 0 };
 		count++;
 
-		numberOfArgs = buffer2array(string, &array);
+		numberOfArgs = cstrtok(string, array, CONF_LINE_TOKEN_MAX);
 
 		for (i = 0; i < numberOfArgs; i++) {
 			if (array[i][0] == CONF_COMMENT)
@@ -277,7 +275,6 @@ void readConf(char *file)
 		argsMinusComment = i;
 
 		if (0 == argsMinusComment) {
-			freeArgArray(array, numberOfArgs);
 			continue;
 		}
 
@@ -316,8 +313,6 @@ void readConf(char *file)
 			param = newConfigParam(array[1], count);
 
 		insertInListWithoutKey(entry->configParamList, param);
-
-		freeArgArray(array, numberOfArgs);
 	}
 	fclose(fp);
 }