This commit adjusts the minimum mmap size from 1MB to 32KB. The
previous limit was arbitrary and causes wasted space for very small
databases.
Thanks to @mcuadros for submitting the original pull request:
https://github.com/boltdb/bolt/pull/351
This commit adds the DB.NoGrowSync flag to optionally revert mmap()
calls to how they were implemented before the ext3/ext4 fix. When
NoGrowSync is true, remapping the data file will not force the file
system to resize it immediately. This works for non-ext3/4 file
systems.
The default value of NoGrowSync is false so it is still safe for
ext3/ext4 file systems by default.
See also: https://github.com/boltdb/bolt/issues/284
Added a few lines of documentation to clarify that read-only
transactions need to be rolled back and not committed, as per the
discussion in issue #344
when accessing the node data we used to use cast to
*[maxAllocSize]byte, which breaks if we try to go across maxAllocSize boundary.
This leads to occasional panics.
Sample stacktrace:
```
panic: runtime error: slice bounds out of range
goroutine 1 [running]:
github.com/boltdb/bolt.(*node).write(0xc208010f50, 0xc27452a000)
$GOPATH/src/github.com/boltdb/bolt/node.go:228 +0x5a5
github.com/boltdb/bolt.(*node).spill(0xc208010f50, 0x0, 0x0)
$GOPATH/src/github.com/boltdb/bolt/node.go:364 +0x506
github.com/boltdb/bolt.(*node).spill(0xc208010700, 0x0, 0x0)
$GOPATH/src/github.com/boltdb/bolt/node.go:336 +0x12d
github.com/boltdb/bolt.(*node).spill(0xc208010620, 0x0, 0x0)
$GOPATH/src/github.com/boltdb/bolt/node.go:336 +0x12d
github.com/boltdb/bolt.(*Bucket).spill(0xc22b6ae880, 0x0, 0x0)
$GOPATH/src/github.com/boltdb/bolt/bucket.go:535 +0x1c4
github.com/boltdb/bolt.(*Bucket).spill(0xc22b6ae840, 0x0, 0x0)
$GOPATH/src/github.com/boltdb/bolt/bucket.go:502 +0xac2
github.com/boltdb/bolt.(*Bucket).spill(0xc22f4e2018, 0x0, 0x0)
$GOPATH/src/github.com/boltdb/bolt/bucket.go:502 +0xac2
github.com/boltdb/bolt.(*Tx).Commit(0xc22f4e2000, 0x0, 0x0)
$GOPATH/src/github.com/boltdb/bolt/tx.go:150 +0x1ee
github.com/boltdb/bolt.(*DB).Update(0xc2080e4000, 0xc24d077508, 0x0, 0x0)
$GOPATH/src/github.com/boltdb/bolt/db.go:483 +0x169
```
It usually happens when working with large (50M/100M) values.
One way to reproduce it is to change maxAllocSize in bolt_amd64.go to 70000 and run the tests.
TestBucket_Put_Large crashes.
This commit adds safety documentation to the data accessor functions
in Bolt as well as the README. This was documented once in the package
level godoc but it's important enough that it should be more clear.
This commit moves the functionality in Tx.Copy() to Tx.WriteTo(). This
allows Tx to be used as an io.WriterTo which makes it easier to mock.
The Tx.Copy() function still exists but it's simply a wrapper around
Tx.WriteTo().
Ben Johnson
Ryan Uber
sasha-s
Oliver
Tim Shannon
Xiang Li
Mike Marcacci
chrislusf
Daniel Speichert
funkygao