From 4bdabcaa9a2fbbe79ca74e0d95447b4da7665601 Mon Sep 17 00:00:00 2001
From: Aaron Culliney <devnull@deadc0de.org>
Date: Sat, 1 Oct 2016 13:03:02 -0700
Subject: [PATCH] Optimize disk6 track switch read/write and improve tracing
 conformance with AppleWin

    - No need to read/write if only changed to a "half track"
    - Fixes one small glitch in boot disk tracing
---
 src/disk.c          | 23 ++++++++++++++---------
 src/test/testdisk.c | 28 ++++++++++++++--------------
 2 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/src/disk.c b/src/disk.c
index 0a17c52d..f6464738 100644
--- a/src/disk.c
+++ b/src/disk.c
@@ -613,20 +613,25 @@ static void _disk6_phaseChange(uint16_t ea) {
     }
 
     if (direction) {
-        if (disk6.disk[disk6.drive].track_dirty) {
-            save_track_data(disk6.drive);
-        }
-        disk6.disk[disk6.drive].track_valid = false;
-        disk6.disk[disk6.drive].phase += direction;
+        int next_phase = cur_phase + direction;
 
-        if (disk6.disk[disk6.drive].phase<0) {
-            disk6.disk[disk6.drive].phase=0;
+        if (next_phase < 0) {
+            next_phase = 0;
         }
 
-        if (disk6.disk[disk6.drive].phase>69) { // AppleWin uses 79 (extra tracks/phases)?
-            disk6.disk[disk6.drive].phase=69;
+        if (next_phase > 69) { // AppleWin uses 79 (extra tracks/phases)?
+            next_phase = 69;
         }
 
+        if ((cur_phase >> 1) != (next_phase >> 1)) {
+            if (disk6.disk[disk6.drive].track_dirty) {
+                save_track_data(disk6.drive);
+            }
+            disk6.disk[disk6.drive].track_valid = false;
+        }
+
+        disk6.disk[disk6.drive].phase = next_phase;
+
 #if DISK_TRACING
         if (test_read_fp) {
             fprintf(test_read_fp, "NEW TRK:%d\n", (disk6.disk[disk6.drive].phase>>1));
diff --git a/src/test/testdisk.c b/src/test/testdisk.c
index a488b59a..ae863c6e 100644
--- a/src/test/testdisk.c
+++ b/src/test/testdisk.c
@@ -40,11 +40,11 @@ static void testdisk_teardown(void *arg) {
 // Disk TESTS ...
 
 #if CONFORMANT_TRACKS
-#define EXPECTED_DISK_TRACE_FILE_SIZE 141350
-#define EXPECTED_DISK_TRACE_SHA "471EB3D01917B1C6EF9F13C5C7BC1ACE4E74C851"
+#define EXPECTED_DISK_TRACE_FILE_SIZE 141348
+#define EXPECTED_DISK_TRACE_SHA "8E2415BB7F0A113BFE048FFE0C076AD4B377D22E"
 #else
-#define EXPECTED_DISK_TRACE_FILE_SIZE 134292
-#define EXPECTED_DISK_TRACE_SHA "19C10B594055D88862A35A45301B2E37A2E7E9F4"
+#define EXPECTED_DISK_TRACE_FILE_SIZE 134290
+#define EXPECTED_DISK_TRACE_SHA "FA47CC59F0CC7E5B1E938FD54A3BD8DB6C930593"
 #endif
 TEST test_boot_disk_bytes() {
     srandom(0);
@@ -91,8 +91,8 @@ TEST test_boot_disk_bytes() {
     PASS();
 }
 
-#define EXPECTED_DISK_TRACE_NIB_FILE_SIZE 147368
-#define EXPECTED_DISK_TRACE_NIB_SHA "1716FE7E79068D85F4EEF3CFEB28EAE8D512E592"
+#define EXPECTED_DISK_TRACE_NIB_FILE_SIZE 147366
+#define EXPECTED_DISK_TRACE_NIB_SHA "CE61D709A344778AB8A8DACED5A38D0D40F1E645"
 TEST test_boot_disk_bytes_nib() {
     test_setup_boot_disk(BLANK_NIB, 0);
     srandom(0);
@@ -140,11 +140,11 @@ TEST test_boot_disk_bytes_nib() {
 }
 
 #if CONFORMANT_TRACKS
-#define EXPECTED_DISK_TRACE_PO_FILE_SIZE 141350
-#define EXPECTED_DISK_TRACE_PO_SHA "6C2170D3AA82F87DD34E177309808199BDCCB018"
+#define EXPECTED_DISK_TRACE_PO_FILE_SIZE 141348
+#define EXPECTED_DISK_TRACE_PO_SHA "41C382A0A508F9A7935532ECFB7A1B6D53956A8D"
 #else
-#define EXPECTED_DISK_TRACE_PO_FILE_SIZE 134292
-#define EXPECTED_DISK_TRACE_PO_SHA "9A6DDCB421B369A4BB7ACC5E40D24B0F38F98711"
+#define EXPECTED_DISK_TRACE_PO_FILE_SIZE 134290
+#define EXPECTED_DISK_TRACE_PO_SHA "E85D7B357B02942772F46332953E59CAB67D85CD"
 #endif
 TEST test_boot_disk_bytes_po() {
     test_setup_boot_disk(BLANK_PO, 0);
@@ -325,10 +325,10 @@ TEST test_savehello_po() {
 
 #if CONFORMANT_TRACKS
 #   define EXPECTED_DISKWRITE_TRACE_DSK_FILE_SIZE 85915
-#   define EXPECTED_DISKWRITE_TRACE_DSK_SHA "727162AD8C2C475BDFE1DEEDAE068215C50A28D1"
+#   define EXPECTED_DISKWRITE_TRACE_DSK_SHA "05A9043B09605546F2BCFD31CB2E48C779227D95"
 #else
 #   define EXPECTED_DISKWRITE_TRACE_DSK_FILE_SIZE 85916
-#   define EXPECTED_DISKWRITE_TRACE_DSK_SHA "A8956DFE0E6CDFB5A2A838971FB9CAB9DC0913BB"
+#   define EXPECTED_DISKWRITE_TRACE_DSK_SHA "06E446C69C4C3522BDEF146B56B0414CA945A588"
 #endif
 #define EXPECTED_BSAVE_DSK_SHA "4DC3AEB266692EB5F8C757F36963F8CCC8056AE4"
 TEST test_disk_bytes_savehello_dsk() {
@@ -627,10 +627,10 @@ TEST test_disk_bytes_savehello_po() {
 #define EXPECTED_OOS_DSK_SHA "D5C5A3FFB43F3C55E1C9E4ABD8580322415E9CE0"
 #if CONFORMANT_TRACKS
 #   define EXPECTED_OOS_DSK_TRACE_FILE_SIZE 4386397
-#   define EXPECTED_OOS_DSK_TRACE_SHA "2451ED08296637220614B1DE2C5AE11AB97ED173"
+#   define EXPECTED_OOS_DSK_TRACE_SHA "FF60D99539047B76B0B441C5907F0FBE3D0B2FCE"
 #else
 #   define EXPECTED_OOS_DSK_TRACE_FILE_SIZE 4386354
-#   define EXPECTED_OOS_DSK_TRACE_SHA "FB1BFF7D1535D30810EED9FD1D98CC054FB6FB1A"
+#   define EXPECTED_OOS_DSK_TRACE_SHA "1304191D985B3D3E528FB462D2CF3677584CD2C3"
 #endif
 TEST test_outofspace_dsk() {
     test_setup_boot_disk(BLANK_DSK, 0);