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Overview
| Comment: | Fix a harmless typo in the rollback journal checksum algorithm description. |
|---|---|
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
ebd7ef38cce0e1fc81509bc6c64d9103 |
| User & Date: | drh 2017-02-15 22:44:16 |
Context
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2017-03-06
| ||
| 19:56 | Merge fixes from the 3.17 branch. check-in: 02cadace0c user: drh tags: trunk | |
|
2017-02-22
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| 12:43 | Fix typos in the documentation reported by Karol Swietlicki. check-in: d24b5395d0 user: drh tags: 3.17 | |
|
2017-02-15
| ||
| 22:44 | Fix a harmless typo in the rollback journal checksum algorithm description. check-in: ebd7ef38cc user: drh tags: trunk | |
| 22:43 | Correct the rollback journal checksum algorithm description. check-in: b69eaea914 user: drh tags: trunk | |
Changes
Changes to pages/fileformat2.in.
1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 |
<ol>
<li>Initialize the checksum to the checksum nonce value found in the
journal header at offset 12.
<li>Initialize index X to be N-200 (where N is the size of a database page
in bytes.
<li>Interpret the byte at offset X into the page as an 8-bit unsigned integer
and add the value of that integer to the checksum.
<li>Subtrace 200 from X.
<li>If X is greater than or equal to zero, go back to step 3.
</ol>)^
<p>The checksum value is used to guard against incomplete writes of
a journal page record following a power failure. A different random nonce
is used each time a transaction is started in order to minimize the risk
that unwritten sectors might by chance contain data from the same page
|
| |
1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 |
<ol>
<li>Initialize the checksum to the checksum nonce value found in the
journal header at offset 12.
<li>Initialize index X to be N-200 (where N is the size of a database page
in bytes.
<li>Interpret the byte at offset X into the page as an 8-bit unsigned integer
and add the value of that integer to the checksum.
<li>Subtract 200 from X.
<li>If X is greater than or equal to zero, go back to step 3.
</ol>)^
<p>The checksum value is used to guard against incomplete writes of
a journal page record following a power failure. A different random nonce
is used each time a transaction is started in order to minimize the risk
that unwritten sectors might by chance contain data from the same page
|