dir said what was there and nothing about what was left. SplitDisk has printed the free figure since it was written, so the machine's own listing was the poorer of the two implementations at describing the same disk. 43 files, 3 directories 46 of 64 entries, 1893 blocks free Entries first, because they are the ceiling nobody notices until they hit it: a disk of small files runs out of directory slots long before it runs out of blocks. COUNTED RATHER THAN ASKED. The superblock keeps a free count and this file calls it "a note rather than the truth" in three places. sbfsSpace reads the whole directory table instead, which costs a read per directory block and is the answer rather than a guess. SplitDisk goes on reading the note and saying when it is stale, which is the right place for that check - the host tool is what you audit a disk with. ---- And it is a fact about the disk, not about where you are ---- The first version added the blocks up as the LISTING walked past them, which cost no extra read and was wrong: that walk stops only on entries in the working directory, so the same disk came out as 1,996 blocks free from the root and 2,025 from /Apps. Comparing against SplitDisk is what said so, which is what having two implementations is for. ---- The longest run, which is what decides whether a file fits ---- 4 of 16 entries, 37 blocks free the longest run is 25 Files are laid down contiguously, so the free total does not say whether a file will fit. Both implementations learn it, from one specification. Said only when it differs from the free total. Deleting is what fragments a contiguous store, and a disk that has only been appended to has one gap at the end - so on a healthy disk this is silent, and a line that appears only when something is wrong is a line somebody reads. There is no sort on this machine and the entries are in no order, so a candidate walks the disk: each pass finds the used extent nearest at or after it, and anything the candidate stands inside pushes it to the far end and starts the pass again. The same trick allocating uses. So it costs a pass per gap rather than per file - nearly nothing on a disk with one gap, more the more fragmented the disk is, which is the right way round. holes.img is six files with the second and fourth deleted, because no other disk here can show any of this: none of them has ever had anything deleted from it. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
1.7 KiB
1.7 KiB
CosmOS
> Crash opcode
that byte is not an instruction, at 5081
A 00 B 0F Q 00
the program was stopped
> Crash service
nothing is installed at service 28, at 5084
A 00 B 0F Q 00
the program was stopped
> Crash bank
a bank that is not there, or an address past its end, at 509E
A 01 B 0F Q 00
the program was stopped
> Crash device
nothing is installed for the device on port 00, at 50A5
A 02 B 0F Q 00
the program was stopped
> Crash sideways
Crash opcode | service | bank | device | blind
finished
> dir
greet.sbx 211
hello.sbx 53
Life.sbx 1396
Snake.sbx 2164
Keys.sbx 664
Say.sbx 156
Where.sbx 827
Break.sbx 149
Grid.sbx 571
Press.sbx 872
Mode.sbx 48
Flip.sbx 173
Sprite.sbx 442
Depth.sbx 672
Packages <dir>
Pad.sbx 264
Crash.sbx 632
vars.script 50
blocks.script 343
loops.script 272
tune.sbx 318
Play.sbx 2526
notes.txt 21
Apps <dir>
hi.script 121
bad.script 45
plain.script 24
cross.script 280
nonl.script 38
outer.script 376
inner.script 44
loop.script 35
hush.script 42
aloud.script 59
args.script 64
pass.script 20
holds.script 87
35 files, 2 directories
46 of 64 entries, 1893 blocks free
> exit
halted
Execution halted.
[exit 0]
> Crash opcode
that byte is not an instruction, at 5081
A 00 B 0F Q 00
the program was stopped
> Crash service
nothing is installed at service 28, at 5084
A 00 B 0F Q 00
the program was stopped
> Crash bank
a bank that is not there, or an address past its end, at 509E
A 01 B 0F Q 00
the program was stopped
> Crash device
nothing is installed for the device on port 00, at 50A5
A 02 B 0F Q 00
the program was stopped
> Crash sideways
Crash opcode | service | bank | device | blind
finished
> dir
greet.sbx 211
hello.sbx 53
Life.sbx 1396
Snake.sbx 2164
Keys.sbx 664
Say.sbx 156
Where.sbx 827
Break.sbx 149
Grid.sbx 571
Press.sbx 872
Mode.sbx 48
Flip.sbx 173
Sprite.sbx 442
Depth.sbx 672
Packages <dir>
Pad.sbx 264
Crash.sbx 632
vars.script 50
blocks.script 343
loops.script 272
tune.sbx 318
Play.sbx 2526
notes.txt 21
Apps <dir>
hi.script 121
bad.script 45
plain.script 24
cross.script 280
nonl.script 38
outer.script 376
inner.script 44
loop.script 35
hush.script 42
aloud.script 59
args.script 64
pass.script 20
holds.script 87
35 files, 2 directories
46 of 64 entries, 1893 blocks free
> exit
halted
Execution halted.
[exit 0]