Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: master
Fetching contributors…

Octocat-spinner-32-eaf2f5

Cannot retrieve contributors at this time

file 361 lines (328 sloc) 10.404 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360
package sqlite3

// #include <sqlite3.h>
// #include <stdlib.h>
// int gosqlite3_prepare_v2(sqlite3* db, const char* zSql, int nByte, sqlite3_stmt **ppStmt) {
// return sqlite3_prepare_v2(db, zSql, nByte, ppStmt, NULL);
// }
import "C"
import (
"fmt"
"strconv"
"strings"
"time"
"unsafe"
)


type DBFlag int

func (d DBFlag) String() string {
flags := []string{}
for i := O_READONLY; i < d; i <<= 1 {
if s, ok := flagText[d & i]; ok {
flags = append(flags, s)
}
}
return strings.Join(flags, "|")
}

const (
O_READONLY DBFlag = 0x00000001
O_READWRITE DBFlag = 0x00000002
O_CREATE DBFlag = 0x00000004
O_DELETEONCLOSE DBFlag = 0x00000008
O_EXCLUSIVE DBFlag = 0x00000010
O_AUTOPROXY DBFlag = 0x00000020
O_URI DBFlag = 0x00000040
O_MAIN_DB DBFlag = 0x00000100
O_TEMP_DB DBFlag = 0x00000200
O_TRANSIENT_DB DBFlag = 0x00000400
O_MAIN_JOURNAL DBFlag = 0x00000800
O_TEMP_JOURNAL DBFlag = 0x00001000
O_SUBJOURNAL DBFlag = 0x00002000
O_MASTER_JOURNAL DBFlag = 0x00004000
O_NOMUTEX DBFlag = 0x00008000
O_FULLMUTEX DBFlag = 0x00010000
O_SHAREDCACHE DBFlag = 0x00020000
O_PRIVATECACHE DBFlag = 0x00040000
O_WAL DBFlag = 0x00080000
)

var flagText = map[DBFlag]string{
O_READONLY: "O_READONLY",
O_READWRITE: "O_READWRITE",
O_CREATE: "O_CREATE",
O_DELETEONCLOSE: "O_DELETEONCLOSE",
O_EXCLUSIVE: "O_EXCLUSIVE",
O_AUTOPROXY: "O_AUTOPROXY",
O_URI: "O_URI",
O_MAIN_DB: "O_MAIN_DB",
O_TEMP_DB: "O_TEMP_DB",
O_TRANSIENT_DB: "O_TRANSIENT_DB",
O_MAIN_JOURNAL: "O_MAIN_JOURNAL",
O_TEMP_JOURNAL: "O_TEMP_JOURNAL",
O_SUBJOURNAL: "O_SUBJOURNAL",
O_MASTER_JOURNAL: "O_MASTER_JOURNAL",
O_NOMUTEX: "O_NOMUTEX",
O_FULLMUTEX: "O_FULLMUTEX",
O_SHAREDCACHE: "O_SHAREDCACHE",
O_PRIVATECACHE: "O_PRIVATECACHE",
O_WAL: "O_WAL",
}

// Database implements high level view of the underlying database.
type Database struct {
handle *C.sqlite3
Filename string
DBFlag
Savepoints []interface{}
}

// TransientDatabase returns a handle to an in-memory database.
func TransientDatabase() (db *Database) {
return &Database{Filename: ":memory:"}
}

// Open returns a handle to the sqlite3 database specified by filename.
func Open(filename string, flags ...DBFlag) (db *Database, e error) {
defer func() {
if x := recover(); x != nil {
db.Close()
db = nil
e = MISUSE
}
}()
db = &Database{Filename: filename}
if len(flags) == 0 {
e = db.Open(O_FULLMUTEX, O_READWRITE, O_CREATE)
} else {
e = db.Open(flags...)
}
return
}

// Open initializes and opens the database.
func (db *Database) Open(flags ...DBFlag) (e error) {
if C.sqlite3_threadsafe() == 0 {
panic("sqlite library is not thread-safe")
}
if db.handle != nil {
e = CANTOPEN
} else {
db.DBFlag = 0
for _, v := range flags {
db.DBFlag |= v
}

cs := C.CString(db.Filename)
defer C.free(unsafe.Pointer(cs))
e = SQLiteError(C.sqlite3_open_v2(cs, &db.handle, C.int(db.DBFlag), nil))

if e == nil && db.handle == nil {
e = CANTOPEN
}
}
return
}

// Close is used to close the database.
func (db *Database) Close() {
C.sqlite3_close(db.handle)
db.handle = nil
}

// LastInsertRowID returns the id of the most recently successful INSERT.
//
// Each entry in an SQLite table has a unique 64-bit signed integer key
// called the "rowid". The rowid is always available as an undeclared column
// named ROWID, OID, or _ROWID_ as long as those names are not also used by
// explicitly declared columns. If the table has a column of type
// INTEGER PRIMARY KEY then that column is another alias for the rowid.
//
// This routine returns the rowid of the most recently successful INSERT into
// the database from the database connection in the first argument. As of
// SQLite version 3.7.7, this routines records the last insert rowid of both
// ordinary tables and virtual tables. If no successful INSERTs have ever
// occurred on that database connection, zero is returned.
func (db *Database) LastInsertRowID() int64 {
return int64(C.sqlite3_last_insert_rowid(db.handle))
}

// Changes returns the number of database rows that were changed or inserted
// or deleted by the most recently completed SQL statement.
func (db *Database) Changes() int {
return int(C.sqlite3_changes(db.handle))
}

// TotalChanges retruns the number of row changes.
//
// This function returns the number of row changes caused by INSERT, UPDATE
// or DELETE statements since the database connection was opened. The count
// returned by TotalChanges includes all changes from all trigger contexts
// and changes made by foreign key actions. However, the count does not
// include changes used to implement REPLACE constraints, do rollbacks or
// ABORT processing, or DROP TABLE processing. The count does not include
// rows of views that fire an INSTEAD OF trigger, though if the INSTEAD OF
// trigger makes changes of its own, those changes are counted. The
// TotalChanges function counts the changes as soon as the statement that
// makes them is completed.
func (db *Database) TotalChanges() int {
return int(C.sqlite3_total_changes(db.handle))
}

// Error returns the numeric result code for the most recently failed database
// call.
func (db *Database) Error() error {
return SQLiteError(C.sqlite3_errcode(db.handle))
}

// Prepare compiles the SQL query into a byte-code program and binds the
// supplied values.
func (db *Database) Prepare(sql string, values ...interface{}) (s *Statement, e error) {
s = &Statement{db: db, timestamp: time.Now().UnixNano()}
cs := C.CString(sql)
defer C.free(unsafe.Pointer(cs))
if e = SQLiteError(C.gosqlite3_prepare_v2(db.handle, cs, -1, &s.cptr)); e != nil {
s = nil
} else {
if len(values) > 0 {
e, _ = s.BindAll(values...)
}
}
return
}

// Execute runs the SQL statement.
func (db *Database) Execute(sql string, f ...func(*Statement, ...interface{})) (c int, e error) {
var st *Statement
if st, e = db.Prepare(sql); e == nil {
c, e = st.All(f...)
}
return
}

// Begin initializes a SQL Transaction block.
func (db *Database) Begin() (e error) {
_, e = db.Execute("BEGIN")
return
}

// Rollback reverts the changes since the most recent Begin() call.
func (db *Database) Rollback() (e error) {
_, e = db.Execute("ROLLBACK")
return
}

// Commit ends the current transaction and makes all changes performed in the
// transaction permanent.
func (db *Database) Commit() (e error) {
_, e = db.Execute("COMMIT")
return
}

func savepointID(id interface{}) (s string) {
switch id := id.(type) {
case string:
s = id
case []byte:
s = string(id)
case fmt.Stringer:
s = id.String()
case int:
s = strconv.Itoa(id)
case uint:
s = strconv.FormatUint(uint64(id), 10)
default:
panic(SAVEPOINT)
}
return
}

// Mark creates a SAVEPOINT.
//
// A SAVEPOINT is a method of creating transactions, similar to BEGIN and
// COMMIT, except that Mark and MergeSteps are named and may be nested.
func (db *Database) Mark(id interface{}) (e error) {
if st, err := db.Prepare("SAVEPOINT ?", savepointID(id)); err == nil {
_, e = st.All()
} else {
e = err
}
return
}

// MergeSteps can be seen as the equivalent of COMMIT for a Mark command.
//
func (db *Database) MergeSteps(id interface{}) (e error) {
if st, err := db.Prepare("RELEASE SAVEPOINT ?", savepointID(id)); err == nil {
_, e = st.All()
} else {
e = err
}
return
}

// Release rolls back all transactions to the specified SAVEPOINT (Mark).
// More specificly ...
// - Some people view RELEASE as the equivalent of COMMIT for a SAVEPOINT.
// This is an acceptable point of view as long as one remembers that the
// changes committed by an inner transaction might later be undone by a
// rollback in an outer transaction.
// - Another view of RELEASE is that it merges a named transaction into its
// parent transaction, so that the named transaction and its parent
// become the same transaction. After RELEASE, the named transaction and
// its parent will commit or rollback together, whatever their fate may
// be.
// - One can also think of savepoints as "marks" in the transaction
// timeline. In this view, the SAVEPOINT command creates a new mark, the
// ROLLBACK TO command rewinds the timeline back to a point just after
// the named mark, and the RELEASE command erases marks from the timeline
// without actually making any changes to the database.
func (db *Database) Release(id interface{}) (e error) {
if st, err := db.Prepare("ROLLBACK TRANSACTION TO SAVEPOINT ?", savepointID(id)); err == nil {
_, e = st.All()
} else {
e = err
}
return
}

// SavePoints returns the currently active SAVEPOINTs created using Mark.
func (db *Database) SavePoints() (s []interface{}) {
s = make([]interface{}, len(db.Savepoints))
copy(s, db.Savepoints)
return
}

// Load creates a backup of the source database and loads that.
func (db *Database) Load(source *Database, dbname string) (e error) {
if dbname == "" {
dbname = "main"
}
if backup, rv := NewBackup(db, dbname, source, dbname); rv == nil {
e = backup.Full()
} else {
e = rv
}
return
}

// Save stores the content of the database in the target database.
func (db *Database) Save(target *Database, dbname string) (e error) {
return target.Load(db, dbname)
}

type Reporter chan *ProgressReport

type BackupParameters struct {
Target string
PagesPerStep int
QueueLength int
Interval time.Duration
Verbose bool
}

// Backup creates a copy (backup) of the current database to the target file
// specified in BackupParameters.
func (db *Database) Backup(p BackupParameters) (r Reporter, e error) {
if target, e := Open(p.Target); e == nil {
if backup, e := NewBackup(target, "main", db, "main"); e == nil && p.PagesPerStep > 0 {
r = make(Reporter, p.QueueLength)
go func() {
defer target.Close()
defer backup.Finish()
defer close(r)
for {
report := &ProgressReport{
Source: db.Filename,
Target: p.Target,
Error: backup.Step(p.PagesPerStep),
Total: backup.PageCount(),
Remaining: backup.Remaining(),
Verbose: p.Verbose,
}
r <- report
if e := report.Error; !(e == nil || e == BUSY || e == LOCKED) {
break
}
if p.Interval > 0 {
time.Sleep(p.Interval)
}
}
}()
} else {
target.Close()
e = target.Error()
}
}
return
}
Something went wrong with that request. Please try again.