switch to chunk-wide read/write loops when loading and dumping in std…

…io mode

This fixes the high CPU usage and slow speeds observed when using
stdio mode and temporary files need to be spilled to disk.

lrzip.c

@@ -56,6 +56,7 @@
 #include "stream.h"
 
 #define MAGIC_LEN (24)
+#define STDIO_TMPFILE_BUFFER_SIZE (65536) // used in read_tmpinfile and dump_tmpoutfile
 
 static void release_hashes(rzip_control *control);
 
@@ -412,7 +413,7 @@ static bool flush_tmpoutbuf(rzip_control *control)
 /* Dump temporary outputfile to perform stdout */
 static bool dump_tmpoutfile(rzip_control *control)
 {
-	int tmpchar, fd_out = control->fd_out;
+	int fd_out = control->fd_out;
 	FILE *tmpoutfp;
 
 	if (unlikely(fd_out == -1))
@@ -425,9 +426,35 @@ static bool dump_tmpoutfile(rzip_control *control)
 	rewind(tmpoutfp);
 
 	if (!TEST_ONLY) {
+		char* buf;
+
 		print_verbose("Dumping temporary file to control->outFILE.\n");
-		while ((tmpchar = fgetc(tmpoutfp)) != EOF)
-			putchar(tmpchar);
+		fflush(control->outFILE);
+
+		buf = malloc(STDIO_TMPFILE_BUFFER_SIZE);
+		if (unlikely(!buf))
+			fatal_return(("Failed to allocate buffer in dump_tmpoutfile\n"), false);
+
+		while (1) {
+			ssize_t num_read, num_written;
+			num_read = fread(buf, 1, STDIO_TMPFILE_BUFFER_SIZE, tmpoutfp);
+			if (unlikely(num_read == 0)) {
+				if (ferror(tmpoutfp)) {
+					dealloc(buf);
+					fatal_return(("Failed read in dump_tmpoutfile\n"), false);
+				} else {
+					break; // must be at EOF
+				}
+			}
+
+			num_written = fwrite(buf, 1, num_read, control->outFILE);
+			if (unlikely(num_written != num_read)) {
+				dealloc(buf);
+				fatal_return(("Failed write in dump_tmpoutfile\n"), false);
+			}
+		}
+
+		dealloc(buf);
 		fflush(control->outFILE);
 		rewind(tmpoutfp);
 	}
@@ -539,6 +566,7 @@ bool read_tmpinfile(rzip_control *control, int fd_in)
 {
 	FILE *tmpinfp;
 	int tmpchar;
+	char* buf;
 
 	if (fd_in == -1)
 		return false;
@@ -548,9 +576,30 @@ bool read_tmpinfile(rzip_control *control, int fd_in)
 	if (unlikely(tmpinfp == NULL))
 		fatal_return(("Failed to fdopen in tmpfile\n"), false);
 
-	while ((tmpchar = getchar()) != EOF)
-		fputc(tmpchar, tmpinfp);
+	buf = malloc(STDIO_TMPFILE_BUFFER_SIZE);
+	if (unlikely(!buf))
+		fatal_return(("Failed to allocate buffer in read_tmpinfile\n"), false);
+
+	while (1) {
+		ssize_t num_read, num_written;
+		num_read = fread(buf, 1, STDIO_TMPFILE_BUFFER_SIZE, stdin);
+		if (unlikely(num_read == 0)) {
+			if (ferror(stdin)) {
+				dealloc(buf);
+				fatal_return(("Failed read in read_tmpinfile\n"), false);
+			} else {
+				break; // must be at EOF
+			}
+		}
+
+		num_written = fwrite(buf, 1, num_read, tmpinfp);
+		if (unlikely(num_written != num_read)) {
+			dealloc(buf);
+			fatal_return(("Failed write in read_tmpinfile\n"), false);
+		}
+	}
 
+	dealloc(buf);
 	fflush(tmpinfp);
 	rewind(tmpinfp);
 	return true;