Also add a link to more information about isolation levels as defined by the
SQL standard. Fixes#17682.
Change-Id: I94c53b713f4c882af40cf15fe5f1e5dbc53ea741
Reviewed-on: https://go-review.googlesource.com/32418
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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Prior to this change, it was implied that transaction properties
would be carried in the context value. However, no such properties
were defined, not even common ones. Define two common properties:
isolation level and read-only. Drivers may choose to support
additional transaction properties. It is not expected any
further transaction properties will be added in the future.
Change-Id: I2f680115a14a1333c65ba6f943d9a1149d412918
Reviewed-on: https://go-review.googlesource.com/31258
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
There was some ambiguity over which argument was referred to when
a conversion error was returned. Now refer to the argument by
either explicit ordinal position or name if present.
Fixes#15676
Change-Id: Id933196b7e648baa664f4121fa3fb1b07b3c4880
Reviewed-on: https://go-review.googlesource.com/31262
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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Missing the DB mutex unlock on an early return after checking
if the context has expired.
Fixes#17518
Change-Id: I247cafcef62623d813f534a941f3d5a3744f0738
Reviewed-on: https://go-review.googlesource.com/31494
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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Creates a ColumnType structure that can be extended in to future.
Allow drivers to implement what makes sense for the database.
Fixes#16652
Change-Id: Ieb1fd64eac1460107b1d3474eba5201fa300a4ec
Reviewed-on: https://go-review.googlesource.com/29961
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The driver.Valuer interface lets types map their Go representation to
a suitable database/sql/driver.Value.
If a user defines the Value method with a value receiver, such as:
type MyStr string
func (s MyStr) Value() (driver.Value, error) {
return strings.ToUpper(string(s)), nil
}
Then they can't use (*MyStr)(nil) as an argument to an SQL call via
database/sql, because *MyStr also implements driver.Value, but via a
compiler-generated wrapper which checks whether the pointer is nil and
panics if so.
We now accept (*MyStr)(nil) and map it to "nil" (an SQL "NULL")
if the Valuer method is implemented on MyStr instead of *MyStr.
If a user implements the driver.Value interface with a pointer
receiver, they retain full control of what nil means:
type MyStr string
func (s *MyStr) Value() (driver.Value, error) {
if s == nil {
return "missing MyStr", nil
}
return strings.ToUpper(string(*s)), nil
}
Adds tests for both cases.
Fixes#8415
Change-Id: I897d609d80d46e2354d2669a8a3e090688eee3ad
Reviewed-on: https://go-review.googlesource.com/31259
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Modify the new Context methods to take a name-value driver struct.
This will require more modifications to drivers to use, but will
reduce the overall number of structures that need to be maintained
over time.
Fixes#12381
Change-Id: I30747533ce418a1be5991a0c8767a26e8451adbd
Reviewed-on: https://go-review.googlesource.com/30166
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Many database systems allow returning multiple result sets
in a single query. This can be useful when dealing with many
intermediate results on the server and there is a need
to return more then one arity of data to the client.
Fixes#12382
Change-Id: I480a9ac6dadfc8743e0ba8b6d868ccf8442a9ca1
Reviewed-on: https://go-review.googlesource.com/30592
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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To prevent leaking connections, close any open Rows when the
context is cancelled. Also enforce context cancel while reading
rows off of the wire.
Change-Id: I62237ecdb7d250d6734f6ce3d2b0bcb16dc6fda7
Reviewed-on: https://go-review.googlesource.com/29957
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Add context methods to sql and sql/driver methods. If
the driver doesn't implement context methods the connection
pool will still handle timeouts when a query fails to return
in time or when a connection is not available from the pool
in time.
There will be a follow-up CL that will add support for
context values that specify transaction levels and modes
that a driver can use.
Fixes#15123
Change-Id: Ia99f3957aa3f177b23044dd99d4ec217491a30a7
Reviewed-on: https://go-review.googlesource.com/29381
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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TestPendingConnsAfterErr only cared that things didn't deadlock, so 5
seconds is a sufficient timer. We don't need 100 milliseconds.
I was able to reproduce with a tiny (5 nanosecond) timeout value,
instead of 100 milliseconds. In the process of testing with -race and
a high -count= value, I noticed several data races and panics
(sendings on a closed channel) which are also fixed in this change.
Fixes#15684
Change-Id: Ib4605fcc0f296e658cb948352ed642b801cb578c
Reviewed-on: https://go-review.googlesource.com/24550
Reviewed-by: Marko Tiikkaja <marko@joh.to>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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Reviewed-by: Andrew Gerrand <adg@golang.org>
Previously named byte types like json.RawMessage could get dirty
database memory from a call to Scan. These types would activate a
code path that didn't clone the byte data coming from the database
before assigning it. Another thread could then overwrite the byte
array in src, which has unexpected consequences.
Originally reported by Jason Moiron; the patch and test are his
suggestions. Fixes#13905.
Change-Id: Iacfef61cbc9dd51c8fccef9b2b9d9544c77dd0e0
Reviewed-on: https://go-review.googlesource.com/22393
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This change removes a lot of dead code. Some of the code has never been
used, not even when it was first commited. The rest shouldn't have
survived refactors.
This change doesn't remove unused routines helpful for debugging, nor
does it remove code that's used in commented out blocks of code that are
only unused temporarily. Furthermore, unused constants weren't removed
when they were part of a set of constants from specifications.
One noteworthy omission from this CL are about 1000 lines of unused code
in cmd/fix, 700 lines of which are the typechecker, which hasn't been
used ever since the pre-Go 1 fixes have been removed. I wasn't sure if
this code should stick around for future uses of cmd/fix or be culled as
well.
Change-Id: Ib714bc7e487edc11ad23ba1c3222d1fd02e4a549
Reviewed-on: https://go-review.googlesource.com/20926
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The exclusion of string from IsScanValue prevents driver authors from
writing their drivers in such a way that would allow users to
distinguish between strings and byte arrays returned from a database.
Such drivers are possible today, but require their authors to deviate
from the guidance provided by the standard library.
This exclusion has been in place since the birth of this package in
https://github.com/golang/go/commit/357f2cb1a385f4d1418e48856f9abe0cce,
but the fakedb implementation shipped in the same commit violates the
exclusion!
Strictly speaking this is a breaking change, but it increases the set
of permissible Scan types, and should not cause breakage in practice.
No test changes are necessary because fakedb already exercises this.
Fixes#6497.
Change-Id: I69dbd3a59d90464bcae8c852d7ec6c97bfd120f8
Reviewed-on: https://go-review.googlesource.com/19439
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
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Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.
This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:
$ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])')
$ go test go/doc -update
Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
You can not use cannot, but you cannot spell cannot can not.
Change-Id: I2f0971481a460804de96fd8c9e46a9cc62a3fc5b
Reviewed-on: https://go-review.googlesource.com/19772
Reviewed-by: Rob Pike <r@golang.org>
For #13677, but there is more to do.
Change-Id: Id1af999dc972d07cdfc771e5855a1a7dca47ca96
Reviewed-on: https://go-review.googlesource.com/18046
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Long lived connections may make some DB operation difficult.
(e.g. retiring load balanced DB server.)
So SetConnMaxLifetime closes long lived connections.
It can be used to limit maximum idle time, too.
Closing idle connections reduces active connections while application is idle
and avoids connections are closed by server side (cause errBadConn while querying).
fixes#9851
Change-Id: I2e8e824219c1bee7f4b885d38ed96d11b7202b56
Reviewed-on: https://go-review.googlesource.com/6580
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Previously with db.maxOpen > 0, db.maxOpen+n failed connection attempts
started concurrently could result in a deadlock. DB.conn and
DB.openNewConnection did not trigger the DB.connectionOpener go routine
after a failed connection attempt. This omission could leave go routines
waiting for DB.connectionOpener forever.
In addition the logic to track the state of the pool was inconsistent.
db.numOpen was sometimes incremented optimistically and sometimes not.
This change harmonizes the logic and eliminates the db.pendingOpens
variable, making the logic easier to understand and maintain.
Fixes#10886
Change-Id: I983c4921a3dacfbd531c3d7f8d2da8a592e9922a
Reviewed-on: https://go-review.googlesource.com/14547
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
In particular, don't assume that one reflect.Value can be assigned to another just because they have the same reflect.Kind.
Fixes#12401
Change-Id: Ia4605a5c46557ff8f8f1d44f26d492850666c6d1
Reviewed-on: https://go-review.googlesource.com/15420
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Fixes a case where the Stmt.Close() function in database/sql discards any error generated by the Close() function of the contained driverStmt.
Fixes#12798
Change-Id: I40384d6165856665b062d15a643e4ecc09d63fda
Reviewed-on: https://go-review.googlesource.com/15178
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Previously Tx.close always passed a nil error to tx.db.putConn. As a
result bad connections were reused, even if the driver returned
driver.ErrBadConn. Adding an err parameter to Tx.close allows it to
receive the driver error from Tx.Commit and Tx.Rollback and pass it
to tx.db.putConn.
Fixes#11264
Change-Id: I142b6b2509fa8d714bbc135cef7281a40803b3b8
Reviewed-on: https://go-review.googlesource.com/13912
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The one in misc/makerelease/makerelease.go is particularly bad and
probably warrants rotating our keys.
I didn't update old weekly notes, and reverted some changes involving
test code for now, since we're late in the Go 1.5 freeze. Otherwise,
the rest are all auto-generated changes, and all manually reviewed.
Change-Id: Ia2753576ab5d64826a167d259f48a2f50508792d
Reviewed-on: https://go-review.googlesource.com/12048
Reviewed-by: Rob Pike <r@golang.org>
Adding a mutex was easier than documenting it, and is consistent with
gob.
Fixes#9847
Change-Id: Ifa94c17e7c11643add81b35431ef840b794d78b1
Reviewed-on: https://go-review.googlesource.com/11682
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Previously if the connection pool was larger than maxBadConnRetries
and there were a lot of bad connections in the pool (for example if
the database server was restarted), a query might have failed with an
ErrBadConn unnecessarily. Instead of trying to guess how many times
to retry, try maxBadConnRetries times and then force a fresh
connection to be used for the last attempt. At the same time, lower
maxBadConnRetries to a smaller value now that it's not that important
to retry so many times from the free connection list.
Fixes#8834
Change-Id: I6542f151a766a658980fb396fa4880ecf5874e3d
Reviewed-on: https://go-review.googlesource.com/2034
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Bug Description:
When reduce db.maxOpen via db.SetMaxOpenConns, the unnecssary
connections won't been released until all other connections are free.
Fixes#9453
Change-Id: I9afb2e4b184139b31029ae53d7f5fd1fdb8d8d7e
Reviewed-on: https://go-review.googlesource.com/2200
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This change provides a convenient way to monitor database connection pool.
Change-Id: I4b3757855b43f3b254acf9312e2a16e2f87840d0
Reviewed-on: https://go-review.googlesource.com/7950
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Previouslly, Stmt.connStmt calls DB.connIfFree on each Stmt.css.
Since Stmt.connStmt locks Stmt.mu, a concurrent use of Stmt causes lock
contention on Stmt.mu.
Additionally, DB.connIfFree locks DB.mu which is shared by DB.addDep and
DB.removeDep.
This change removes DB.connIfFree and makes use of a first unused
connection in idle connection pool to reduce lock contention
without making it complicated.
Fixes#9484
On EC2 c3.8xlarge (E5-2680 v2 @ 2.80GHz * 32 vCPU):
benchmark old ns/op new ns/op delta
BenchmarkManyConcurrentQuery-8 40249 34721 -13.73%
BenchmarkManyConcurrentQuery-16 45610 40176 -11.91%
BenchmarkManyConcurrentQuery-32 109831 43179 -60.69%
benchmark old allocs new allocs delta
BenchmarkManyConcurrentQuery-8 25 25 +0.00%
BenchmarkManyConcurrentQuery-16 25 25 +0.00%
BenchmarkManyConcurrentQuery-32 25 25 +0.00%
benchmark old bytes new bytes delta
BenchmarkManyConcurrentQuery-8 3980 3969 -0.28%
BenchmarkManyConcurrentQuery-16 3980 3982 +0.05%
BenchmarkManyConcurrentQuery-32 3993 3990 -0.08%
Change-Id: Ic96296922c465bac38a260018c58324dae1531d9
Reviewed-on: https://go-review.googlesource.com/2207
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
numCanOpen will never be larger than 0 in maybeOpenNewConnections() when this
code path is taken, so no new connections can ever be opened.
Change-Id: Id1302e8d9afb3a67be61b5e738fe07ef81d20fe0
Reviewed-on: https://go-review.googlesource.com/1550
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
