use constant pointers when possible

It is a good practice to constify pointers when their dereferenced
data is not modified within the functions or its descendants.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7234 09075e82-0dd4-0310-85a5-a0d7c8717e4f

3 files changed, 24 insertions, 25 deletions

diff --git a/src/listen.c b/src/listen.c
index a22427095..78bb6ace1 100644
--- a/src/listen.c
+++ b/src/listen.c
@@ -67,7 +67,7 @@ static void redirect_stdin(void)
 		FATAL("dup2 stdin: %s\n", strerror(errno));
 }
 
-static int establishListen(struct sockaddr *addrp, socklen_t addrlen)
+static int establishListen(const struct sockaddr *addrp, socklen_t addrlen)
 {
 	int pf;
 	int sock;
@@ -121,7 +121,7 @@ static int establishListen(struct sockaddr *addrp, socklen_t addrlen)
 
 static void parseListenConfigParam(unsigned int port, ConfigParam * param)
 {
-	struct sockaddr *addrp;
+	const struct sockaddr *addrp;
 	socklen_t addrlen;
 	struct sockaddr_in sin4;
 #ifdef HAVE_IPV6
@@ -141,14 +141,14 @@ static void parseListenConfigParam(unsigned int port, ConfigParam * param)
 #ifdef HAVE_IPV6
 		if (useIpv6) {
 			sin6.sin6_addr = in6addr_any;
-			addrp = (struct sockaddr *)&sin6;
+			addrp = (const struct sockaddr *)&sin6;
 			addrlen = sizeof(struct sockaddr_in6);
 			if (establishListen(addrp, addrlen) < 0)
 				BINDERROR();
 		}
 #endif
 		sin4.sin_addr.s_addr = INADDR_ANY;
-		addrp = (struct sockaddr *)&sin4;
+		addrp = (const struct sockaddr *)&sin4;
 		addrlen = sizeof(struct sockaddr_in);
 #ifdef HAVE_IPV6
 		if ((establishListen(addrp, addrlen) < 0) && !useIpv6) {
@@ -173,14 +173,14 @@ static void parseListenConfigParam(unsigned int port, ConfigParam * param)
 				      param->value, param->line);
 			}
 			memcpy((char *)&sin6.sin6_addr.s6_addr,
-			       (char *)he->h_addr, he->h_length);
-			addrp = (struct sockaddr *)&sin6;
+			       (const char *)he->h_addr, he->h_length);
+			addrp = (const struct sockaddr *)&sin6;
 			addrlen = sizeof(struct sockaddr_in6);
 			break;
 #endif
 		case AF_INET:
 			memcpy((char *)&sin4.sin_addr.s_addr,
-			       (char *)he->h_addr, he->h_length);
+			       (const char *)he->h_addr, he->h_length);
 			addrp = (struct sockaddr *)&sin4;
 			addrlen = sizeof(struct sockaddr_in);
 			break;
diff --git a/src/pcm_utils.c b/src/pcm_utils.c
index be32729f0..6a97fff37 100644
--- a/src/pcm_utils.c
+++ b/src/pcm_utils.c
@@ -74,15 +74,15 @@ void pcm_volumeChange(char *buffer, int bufferSize, AudioFormat * format,
 	}
 }
 
-static void pcm_add(char *buffer1, char *buffer2, size_t bufferSize1,
+static void pcm_add(char *buffer1, const char *buffer2, size_t bufferSize1,
                     size_t bufferSize2, int vol1, int vol2,
-                    AudioFormat * format)
+                    const AudioFormat * format)
 {
 	mpd_sint32 temp32;
 	mpd_sint8 *buffer8_1 = (mpd_sint8 *) buffer1;
-	mpd_sint8 *buffer8_2 = (mpd_sint8 *) buffer2;
+	const mpd_sint8 *buffer8_2 = (const mpd_sint8 *) buffer2;
 	mpd_sint16 *buffer16_1 = (mpd_sint16 *) buffer1;
-	mpd_sint16 *buffer16_2 = (mpd_sint16 *) buffer2;
+	const mpd_sint16 *buffer16_2 = (const mpd_sint16 *) buffer2;
 
 	switch (format->bits) {
 	case 16:
@@ -129,8 +129,8 @@ static void pcm_add(char *buffer1, char *buffer2, size_t bufferSize1,
 	}
 }
 
-void pcm_mix(char *buffer1, char *buffer2, size_t bufferSize1,
-             size_t bufferSize2, AudioFormat * format, float portion1)
+void pcm_mix(char *buffer1, const char *buffer2, size_t bufferSize1,
+             size_t bufferSize2, const AudioFormat * format, float portion1)
 {
 	int vol1;
 	float s = sin(M_PI_2 * portion1);
@@ -351,8 +351,8 @@ static char *pcm_convertChannels(mpd_sint8 channels, char *inBuffer,
 	return outBuffer;
 }
 
-static char *pcm_convertTo16bit(mpd_sint8 bits, char *inBuffer, size_t inSize,
-                                size_t *outSize)
+static char *pcm_convertTo16bit(mpd_sint8 bits, const char *inBuffer,
+				size_t inSize, size_t *outSize)
 {
 	static char *buf;
 	static size_t len;
@@ -378,8 +378,7 @@ static char *pcm_convertTo16bit(mpd_sint8 bits, char *inBuffer, size_t inSize,
 		break;
 	case 16:
 		*outSize = inSize;
-		outBuffer = inBuffer;
-		break;
+		return inBuffer;
 	case 24:
 		/* put dithering code from mp3_decode here */
 	default:
@@ -390,7 +389,7 @@ static char *pcm_convertTo16bit(mpd_sint8 bits, char *inBuffer, size_t inSize,
 }
 
 /* outFormat bits must be 16 and channels must be 1 or 2! */
-size_t pcm_convertAudioFormat(AudioFormat * inFormat, char *inBuffer,
+size_t pcm_convertAudioFormat(AudioFormat * inFormat, const char *inBuffer,
                               size_t inSize, AudioFormat * outFormat,
                               char *outBuffer, ConvState *convState)
 {
@@ -427,8 +426,8 @@ size_t pcm_convertAudioFormat(AudioFormat * inFormat, char *inBuffer,
 	return len;
 }
 
-size_t pcm_sizeOfConvBuffer(AudioFormat * inFormat, size_t inSize,
-                            AudioFormat * outFormat)
+size_t pcm_sizeOfConvBuffer(const AudioFormat * inFormat, size_t inSize,
+                            const AudioFormat * outFormat)
 {
 	const double ratio = (double)outFormat->sampleRate /
 	                     (double)inFormat->sampleRate;
diff --git a/src/pcm_utils.h b/src/pcm_utils.h
index 7362cb7b8..752fac3e7 100644
--- a/src/pcm_utils.h
+++ b/src/pcm_utils.h
@@ -45,13 +45,13 @@ typedef struct _ConvState {
 void pcm_volumeChange(char *buffer, int bufferSize, AudioFormat * format,
                       int volume);
 
-void pcm_mix(char *buffer1, char *buffer2, size_t bufferSize1,
-             size_t bufferSize2, AudioFormat * format, float portion1);
+void pcm_mix(char *buffer1, const char *buffer2, size_t bufferSize1,
+             size_t bufferSize2, const AudioFormat * format, float portion1);
 
-size_t pcm_convertAudioFormat(AudioFormat * inFormat, char *inBuffer,
+size_t pcm_convertAudioFormat(AudioFormat * inFormat, const char *inBuffer,
                               size_t inSize, AudioFormat * outFormat,
                               char *outBuffer, ConvState *convState);
 
-size_t pcm_sizeOfConvBuffer(AudioFormat * inFormat, size_t inSize,
-                            AudioFormat * outFormat);
+size_t pcm_sizeOfConvBuffer(const AudioFormat * inFormat, size_t inSize,
+                            const AudioFormat * outFormat);
 #endif