database/sql: reordering fields to reduce struct sizes

There are 16 bytes reduced.

Change-Id: I33ca96fd22002b3111f0462c3029d70df48adb6e
GitHub-Last-Rev: 8df56a9655ef261be3ff9403491cbbe1ebda1ec0
GitHub-Pull-Request: golang/go#67055
Reviewed-on: https://go-review.googlesource.com/c/go/+/581935
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>

diff --git a/src/database/sql/sql.go b/src/database/sql/sql.go
index fdbe4b21724a79dee79df3059fa05623dd4fbc40..9373aa1c5896c6aa52d92ce9fed255db42b4fdbb 100644 (file)
--- a/src/database/sql/sql.go
+++ b/src/database/sql/sql.go
@@ -551,9 +551,9 @@ type driverConn struct {
 
        // guarded by db.mu
        inUse      bool
+       dbmuClosed bool      // same as closed, but guarded by db.mu, for removeClosedStmtLocked
        returnedAt time.Time // Time the connection was created or returned.
        onPut      []func()  // code (with db.mu held) run when conn is next returned
-       dbmuClosed bool      // same as closed, but guarded by db.mu, for removeClosedStmtLocked
 }
 
 func (dc *driverConn) releaseConn(err error) {
@@ -2923,19 +2923,8 @@ type Rows struct {
        //
        // closemu guards lasterr and closed.
        closemu sync.RWMutex
-       closed  bool
        lasterr error // non-nil only if closed is true
-
-       // lastcols is only used in Scan, Next, and NextResultSet which are expected
-       // not to be called concurrently.
-       lastcols []driver.Value
-
-       // raw is a buffer for RawBytes that persists between Scan calls.
-       // This is used when the driver returns a mismatched type that requires
-       // a cloning allocation. For example, if the driver returns a *string and
-       // the user is scanning into a *RawBytes, we need to copy the string.
-       // The raw buffer here lets us reuse the memory for that copy across Scan calls.
-       raw []byte
+       closed  bool
 
        // closemuScanHold is whether the previous call to Scan kept closemu RLock'ed
        // without unlocking it. It does that when the user passes a *RawBytes scan
@@ -2951,6 +2940,17 @@ type Rows struct {
        // returning. It's only used by Next and Err which are
        // expected not to be called concurrently.
        hitEOF bool
+
+       // lastcols is only used in Scan, Next, and NextResultSet which are expected
+       // not to be called concurrently.
+       lastcols []driver.Value
+
+       // raw is a buffer for RawBytes that persists between Scan calls.
+       // This is used when the driver returns a mismatched type that requires
+       // a cloning allocation. For example, if the driver returns a *string and
+       // the user is scanning into a *RawBytes, we need to copy the string.
+       // The raw buffer here lets us reuse the memory for that copy across Scan calls.
+       raw []byte
 }
 
 // lasterrOrErrLocked returns either lasterr or the provided err.