Add string-buffer output via snd_output_*()

With the configure option, the strings can be output to a buffer.
Otherwise, ignores with dummy funtions.

4 files changed, 185 insertions, 27 deletions

diff --git a/configure.ac b/configure.ac
index d600332..8b9290d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -153,6 +153,18 @@ else
 fi
 AC_SUBST(SALSA_MARK_DEPRECATED)
 
+AC_ARG_ENABLE(output-buffer,
+  AS_HELP_STRING([--enable-output-buffer],
+		 [support the string output via snd_output_*() functions]),
+  output_buffer="$enableval", output_buffer="no")
+
+if test "$output_buffer" = "yes"; then
+  SALSA_SUPPORT_OUTPUT_BUFFER=1
+else
+  SALSA_SUPPORT_OUTPUT_BUFFER=0
+fi
+AC_SUBST(SALSA_SUPPORT_OUTPUT_BUFFER)
+
 AC_ARG_ENABLE(libasound,
   AS_HELP_STRING([--disable-delight-valgrind],
 		 [do not initialize unnecessary fields for ioctls]),
@@ -196,3 +208,4 @@ echo "  - TLV (dB) support: $tlv"
 echo "  - Async handler support: $async"
 echo "  - Make ABI-compatible libasound.so: $libasound"
 echo "  - Mark deprecated attribute: $markdeprecated"
+echo "  - Support string-output via snd_output: $output_buffer"
diff --git a/src/output.h b/src/output.h
index a2d3186..c68037e 100644
--- a/src/output.h
+++ b/src/output.h
@@ -24,14 +24,38 @@
 
 #include <stdio.h>
 #include <errno.h>
-
-typedef FILE snd_output_t;
+#include <stdarg.h>
 
 typedef enum _snd_output_type {
 	SND_OUTPUT_STDIO,
-	/* SND_OUTPUT_BUFFER */
+	SND_OUTPUT_BUFFER
 } snd_output_type_t;
 
+
+#if SALSA_SUPPORT_OUTPUT_BUFFER
+
+typedef struct snd_output snd_output_t;
+
+extern int snd_output_stdio_open(snd_output_t **outputp, const char *file, const char *mode);
+extern int snd_output_stdio_attach(snd_output_t **outputp, FILE *fp, int _close);
+extern int snd_output_close(snd_output_t *out);
+extern int snd_output_printf(snd_output_t *out, const char *fmt, ...);
+extern int snd_output_puts(snd_output_t *out, const char *str);
+extern int snd_output_putc(snd_output_t *out, int c);
+extern int snd_output_flush(snd_output_t *out);
+extern int snd_output_buffer_open(snd_output_t **outputp);
+extern size_t snd_output_buffer_string(snd_output_t *output, char **buf);
+
+#else /* SALSA_SUPPORT_OUTPUT_BUFFER */
+
+/*
+ * Simplified version; don't support the string output
+ */
+
+typedef FILE snd_output_t;
+
+#define _SALSA_BUF_OUT	(snd_output_t *)-1
+
 __SALSA_EXPORT_FUNC
 int snd_output_stdio_open(snd_output_t **outputp, const char *file, const char *mode)
 {
@@ -47,22 +71,66 @@ int snd_output_stdio_attach(snd_output_t **outputp, FILE *fp, int _close)
 	return 0;
 }
 
-#define snd_output_close(out)			fclose(out)
-#define snd_output_printf			fprintf
-#define snd_output_puts(out, str)		fputs(str, out)
-#define snd_output_putc(out, c)			putc(c, out)
-#define snd_output_flush(out)			fflush(out)
+__SALSA_EXPORT_FUNC
+int snd_output_close(snd_output_t *out)
+{
+	if (out != _SALSA_BUF_OUT && out != stdout && out != stderr)
+		return fclose(out);
+	return 0;
+}
+
+__SALSA_EXPORT_FUNC
+int snd_output_printf(snd_output_t *out, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+	if (out == _SALSA_BUF_OUT)
+		return 0;
+	va_start(ap, fmt);
+	ret = vfprintf(out, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+__SALSA_EXPORT_FUNC
+int snd_output_puts(snd_output_t *out, const char *str)
+{
+	if (out != _SALSA_BUF_OUT)
+		return fputs(str, out);
+	return 0;
+}
+
+__SALSA_EXPORT_FUNC
+int snd_output_putc(snd_output_t *out, int c)
+{
+	if (out != _SALSA_BUF_OUT)
+		return putc(c, out);
+	return 0;
+}
+
+__SALSA_EXPORT_FUNC
+int snd_output_flush(snd_output_t *out)
+{
+	if (out != _SALSA_BUF_OUT)
+		return fflush(out);
+	return 0;
+}
 
 __SALSA_EXPORT_FUNC __SALSA_NOT_IMPLEMENTED
 int snd_output_buffer_open(snd_output_t **outputp)
 {
-	return -ENXIO;
+	*outputp = _SALSA_BUF_OUT;
+	return 0;
 }
 
 __SALSA_EXPORT_FUNC __SALSA_NOT_IMPLEMENTED
 size_t snd_output_buffer_string(snd_output_t *output, char **buf)
 {
+	static char tmp[1];
+	*buf = tmp;
 	return 0;
 }
 
+#endif /* SALSA_SUPPORT_OUTPUT_BUFFER */
+
 #endif /* __ALSA_OUTPUT_H */
diff --git a/src/output_abi.c b/src/output_abi.c
index bb689af..f5fc58c 100644
--- a/src/output_abi.c
+++ b/src/output_abi.c
@@ -4,31 +4,68 @@
 #include <stdio.h>
 #include <errno.h>
 #include <stdarg.h>
+#include <string.h>
+#include <stdlib.h>
 #include <unistd.h>
 
-typedef FILE snd_output_t;
+#include "recipe.h"
+#include "global.h"
+#undef __SALSA_EXPORT_FUNC
+#define __SALSA_EXPORT_FUNC
+#include "output.h"
 
-typedef enum _snd_output_type {
-	SND_OUTPUT_STDIO,
-	/* SND_OUTPUT_BUFFER */
-} snd_output_type_t;
+#if SALSA_SUPPORT_OUTPUT_BUFFER
+
+#define CHUNK 4000
+
+struct snd_output {
+	int mode;
+	void *ptr;
+	int len;
+	int size;
+};
+
+int snd_output_stdio_attach(snd_output_t **outputp, FILE *fp, int _close)
+{
+	snd_output_t *out;
+	out = malloc(sizeof(*out));
+	if (!out)
+		return -ENOMEM;
+	out->mode = SND_OUTPUT_STDIO;
+	out->ptr = fp;
+	out->len = _close;
+	*outputp = out;
+	return 0;
+}
 
 int snd_output_stdio_open(snd_output_t **outputp, const char *file, const char *mode)
 {
-	if ((*outputp = fopen(file, mode)) == NULL)
+	FILE *fp = fopen(file, mode);
+	if (!fp)
 		return -errno;
-	return 0;
+	return snd_output_stdio_attach(outputp, fp, 1);
 }
 
-int snd_output_stdio_attach(snd_output_t **outputp, FILE *fp, int _close)
+int snd_output_close(snd_output_t *out)
 {
-	*outputp = fp;
+	if (out->mode == SND_OUTPUT_STDIO) {
+		if (out->len)
+			return fclose(out->ptr);
+	} else
+		free(out->ptr);
+	free(out);
 	return 0;
 }
 
-int snd_output_close(snd_output_t *out)
+static int resize(snd_output_t *out, int new)
 {
-	return fclose(out);
+	int size = out->len + new + CHUNK;
+	void *buf = realloc(out->ptr, size);
+	if (!buf)
+		return -ENOMEM;
+	out->ptr = buf;
+	out->size = size;
+	return 0;
 }
 
 int snd_output_printf(snd_output_t *out, const char *fmt, ...)
@@ -36,32 +73,69 @@ int snd_output_printf(snd_output_t *out, const char *fmt, ...)
 	va_list ap;
 	int ret;
 	va_start(ap, fmt);
-	ret = vfprintf(out, fmt, ap);
+	if (out->mode == SND_OUTPUT_STDIO)
+		ret = vfprintf(out->ptr, fmt, ap);
+	else {
+		ret = vsnprintf(out->ptr + out->len, out->size - out->len,
+				fmt, ap);
+		if (ret >= out->size - out->len) {
+			if (resize(out, ret) < 0)
+				return -ENOMEM;
+			ret = vsnprintf(out->ptr + out->len,
+					out->size - out->len,
+					fmt, ap);
+		}
+	}
 	va_end(ap);
 	return ret;
 }
 
 int snd_output_puts(snd_output_t *out, const char *str)
 {
-	return fputs(str, out);
+	if (out->mode == SND_OUTPUT_STDIO)
+		return fputs(str, out->ptr);
+	else {
+		int len = strlen(str);
+		if (out->size - out->len <= len && resize(out, len) < 0)
+			return -ENOMEM;
+		strcpy(out->ptr + len, str);
+		return len;
+	}
 }
 
 int snd_output_putc(snd_output_t *out, int c)
 {
-	return putc(c, out);
+	if (out->mode == SND_OUTPUT_STDIO)
+		return putc(c, out->ptr);
+	if (out->len + 1 >= out->size && resize(out, 1) < 0)
+		return -ENOMEM;
+	((char *)out->ptr)[out->len++] = c;
+	return 0;
 }
 
 int snd_output_flush(snd_output_t *out)
 {
-	return fflush(out);
+	if (out->mode == SND_OUTPUT_STDIO)
+		return fflush(out->ptr);
+	else
+		out->len = 0;
+	return 0;
 }
 
 int snd_output_buffer_open(snd_output_t **outputp)
 {
-	return -ENXIO;
+	snd_output_t *out = calloc(1, sizeof(*out));
+	if (!out)
+		return -ENOMEM;
+	out->mode = SND_OUTPUT_BUFFER;
+	*outputp = out;
+	return resize(out, 0);
 }
 
-size_t snd_output_buffer_string(snd_output_t *output, char **buf)
+size_t snd_output_buffer_string(snd_output_t *out, char **buf)
 {
-	return 0;
+	*buf = out->ptr;
+	return out->len;
 }
+
+#endif /* !SALSA_SIMPLE_OUTPUT */
diff --git a/src/recipe.h.in b/src/recipe.h.in
index 5b0bb2b..24ef2e2 100644
--- a/src/recipe.h.in
+++ b/src/recipe.h.in
@@ -13,6 +13,9 @@
 /* Enable deprecated attribute for non-working functions */
 #define SALSA_MARK_DEPRECATED	@SALSA_MARK_DEPRECATED@
 
+/* Don't support string output via snd_output_*() */
+#define SALSA_SIMPLE_OUTPUT	@SALSA_SIMPLE_OUTPUT@
+
 #define SALSA_DEVPATH "@DEVPATH@"
 
 #endif /* __ALSA_RECIPE_H */