AnachronautandClaude Opus 5
323d7a0330
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
59 lines
1.3 KiB
Plaintext
59 lines
1.3 KiB
Plaintext
CosmOS
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> drive 1
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> Copy 1:/twoblocks.txt 0:/crossed.txt
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copied
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finished
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> drive
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1
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> Say from drive one
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it says: from drive one
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finished
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> drive
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1
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> cd 0:/
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> dir
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greet.sbx 211
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hello.sbx 53
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Life.sbx 1396
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Snake.sbx 2164
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Keys.sbx 664
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Say.sbx 156
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Where.sbx 827
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Break.sbx 149
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Grid.sbx 571
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Press.sbx 872
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Mode.sbx 48
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Flip.sbx 173
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Sprite.sbx 442
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Depth.sbx 672
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Packages <dir>
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Pad.sbx 264
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Crash.sbx 632
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vars.script 50
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blocks.script 343
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loops.script 272
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tune.sbx 318
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Play.sbx 2526
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notes.txt 21
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Apps <dir>
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hi.script 121
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bad.script 45
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plain.script 24
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cross.script 280
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nonl.script 38
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outer.script 376
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inner.script 44
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loop.script 35
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hush.script 42
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aloud.script 59
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args.script 64
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pass.script 20
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holds.script 87
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crossed.txt 560
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36 files, 2 directories
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47 of 64 entries, 1890 blocks free
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> exit
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halted
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Execution halted.
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[exit 0]
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