stdio error handling is such a pain

2 files changed, 41 insertions, 24 deletions

diff --git a/src/freenect-server.c b/src/freenect-server.c
index 286455b..94f307c 100644
--- a/src/freenect-server.c
+++ b/src/freenect-server.c
@@ -44,6 +44,20 @@ void stop(int sig);
 		exitcode = stat; \
 		stop(0); \
 	} while(0)
+#define stdioerror(stream, name) do {	  \
+		if (feof(stream)) { \
+			error(0, 0, "%s: EOF", name); \
+		} else { \
+			if (ferror(stream)) { \
+				fflush(stream); \
+				error(0, errno, "%s", name); \
+			} else { \
+				error(0, 0, "%s: panic: neither feof nor ferror", name); \
+			} \
+			exitcode = EXIT_FAILURE; \
+		} \
+		stop(0); \
+	} while(0)
 
 struct mpjpg_encoder {
 	struct jpeg_error_mgr jpeg_encoder_err;
@@ -96,12 +110,13 @@ void write_imageframe(const char *name, FILE *stream, struct mpjpg_encoder *e, J
 	            "Content-length: %lu\r\n"
 	            "\r\n",
 	            e->jpeg_len) < 1)
-		threaderror(EXIT_FAILURE, ferror(stream), "%s: writing header", name);
+		stdioerror(stream, name);
 	if (fwrite(e->jpeg_buf, e->jpeg_len, 1, stream) < 1)
-		threaderror(EXIT_FAILURE, ferror(stream), "%s: writing body", name);
+		stdioerror(stream, name);
 	if (fwrite("\r\n", 2, 1, stream) < 1)
-		threaderror(EXIT_FAILURE, ferror(stream), "%s: writing footer", name);
-	fflush(stream);
+		stdioerror(stream, name);
+	if (fflush(stream) != 0)
+		stdioerror(stream, name);
 }
 
 void handle_accel(freenect_device *dev UNUSED, freenect_raw_tilt_state* data) {
@@ -141,9 +156,10 @@ void handle_accel(freenect_device *dev UNUSED, freenect_raw_tilt_state* data) {
 	        "\r\n"
 	        "%s\r\n",
 	            len, json) < 0)
-		threaderror(EXIT_FAILURE, ferror(accel_stream), "accel.mjson: write");
+		stdioerror(accel_stream, "accel.mjson");
 	free(json);
-	fflush(accel_stream);
+	if (fflush(accel_stream) != 0)
+		threaderror(EXIT_FAILURE, errno, "accel.mjson");
 }
 
 uint8_t depth_rgb[640*480*3];
diff --git a/src/multipart-replace.c b/src/multipart-replace.c
index 1f7a75c..658d634 100644
--- a/src/multipart-replace.c
+++ b/src/multipart-replace.c
@@ -27,7 +27,7 @@
 #include "multipart-replace.h"
 #include "util.h"
 
-#define error(stat, errnum, ...) do { \
+#define threaderror(stat, errnum, ...) do { \
 		error(0, errnum, __VA_ARGS__); \
 		ret = stat; \
 		goto end; \
@@ -36,9 +36,9 @@
 		if (feof(stream)) { \
 			error(0, 0, "%s: EOF", name); \
 		} else { \
-			int err = ferror(stream); \
-			if (err != 0) { \
-				error(0, err, "%s", name); \
+			if (ferror(stream)) { \
+				fflush(stream); \
+				error(0, errno, "%s", name); \
 			} else { \
 				error(0, 0, "%s: panic: neither feof nor ferror", name); \
 			} \
@@ -95,7 +95,7 @@ int multipart_replace_reader(struct multipart_replace_stream *s, int fd, const c
 		} while (strcmp(line_buf, "\r\n") == 0);
 		/* make sure it matches the boundary separator */
 		if (strcmp(line_buf, boundary) != 0)
-			error(EXIT_FAILURE, 0, "line does not match boundary: \"%s\"", line_buf);
+			threaderror(EXIT_FAILURE, 0, "line does not match boundary: \"%s\"", line_buf);
 		/* read the frame header (MIME headers) */
 		s->back->len = 0;
 		do {
@@ -114,7 +114,7 @@ int multipart_replace_reader(struct multipart_replace_stream *s, int fd, const c
 		} while (strcmp(line_buf, "\r\n") != 0);
 		/* make sure that it included a Content-length header */
 		if (content_length < 0)
-			error(EXIT_FAILURE, 0, "did not get frame length");
+			threaderror(EXIT_FAILURE, 0, "did not get frame length");
 		/* read the frame contents */
 		if ((ssize_t)s->back->cap < s->back->len + content_length)
 			s->back->buf = xrealloc(s->back->buf, s->back->cap = s->back->len + content_length);
@@ -152,20 +152,21 @@ int multipart_replace_writer(struct multipart_replace_stream *s, int fd, const c
 		if (myframe.cap < (size_t)s->front->len)
 			myframe.buf = xrealloc(myframe.buf, myframe.cap = s->front->len);
 		memcpy(myframe.buf, s->front->buf, myframe.len = s->front->len);
-
 		pthread_rwlock_unlock(&s->frontlock);
 
-		if (myframe.len != 0) {
-			/* send the frame to the client */
-			if (fwrite(boundary, boundary_len, 1, stream) < 1)
-				stdioerror(stream, "dst <- boundary");
-			if (fwrite(myframe.buf, myframe.len, 1, stream) < 1)
-				stdioerror(stream, "dst <- frame");
-			/* send a blank line for pleasantness */
-			if (fwrite("\r\n", 2, 1, stream) < 1)
-				stdioerror(stream, "dst <- nl");
-			fflush(stream);
-		}
+		if (myframe.len == 0)
+			threaderror(EXIT_FAILURE, 0, "got empty frame");
+
+		/* send the frame to the client */
+		if (fwrite(boundary, boundary_len, 1, stream) < 1)
+			stdioerror(stream, "dst <- boundary");
+		if (fwrite(myframe.buf, myframe.len, 1, stream) < 1)
+			stdioerror(stream, "dst <- frame");
+		/* send a blank line for pleasantness */
+		if (fwrite("\r\n", 2, 1, stream) < 1)
+			stdioerror(stream, "dst <- nl");
+		if (fflush(stream) != 0)
+			threaderror(EXIT_FAILURE, errno, "dst");
 	}
  end:
 	free(boundary);