nwaku/waku/common/databases/db_sqlite.nim

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{.push raises: [].}
# The code in this file is an adaptation of the Sqlite KV Store found in nim-eth.
# https://github.com/status-im/nim-eth/blob/master/eth/db/kvstore_sqlite3.nim
#
# Most of it is a direct copy, the only unique functions being `get` and `put`.
import
std/[os, strutils, sequtils, algorithm],
stew/results,
chronicles,
sqlite3_abi
import
./common
logScope:
topics = "sqlite"
type
Sqlite = ptr sqlite3
NoParams* = tuple
RawStmtPtr* = ptr sqlite3_stmt
SqliteStmt*[Params; Result] = distinct RawStmtPtr
AutoDisposed[T: ptr|ref] = object
val: T
template dispose(db: Sqlite) =
discard sqlite3_close(db)
template dispose(rawStmt: RawStmtPtr) =
discard sqlite3_finalize(rawStmt)
template dispose*(sqliteStmt: SqliteStmt) =
discard sqlite3_finalize(RawStmtPtr sqliteStmt)
proc release[T](x: var AutoDisposed[T]): T =
result = x.val
x.val = nil
proc disposeIfUnreleased[T](x: var AutoDisposed[T]) =
mixin dispose
if x.val != nil:
dispose(x.release)
template checkErr*(op, cleanup: untyped) =
if (let v = (op); v != SQLITE_OK):
cleanup
return err($sqlite3_errstr(v))
template checkErr*(op) =
checkErr(op): discard
type
SqliteDatabase* = ref object of RootObj
env*: Sqlite
type DataProc* = proc(s: RawStmtPtr) {.closure.} # the nim-eth definition is different; one more indirection
const NoopRowHandler* = proc(s: RawStmtPtr) {.closure.} = discard
proc new*(T: type SqliteDatabase,
path: string,
readOnly=false):
DatabaseResult[T] =
var env: AutoDisposed[ptr sqlite3]
defer: disposeIfUnreleased(env)
let flags = if readOnly: SQLITE_OPEN_READONLY
else: SQLITE_OPEN_READWRITE or SQLITE_OPEN_CREATE
if path != ":memory:":
try:
createDir(parentDir(path))
except OSError, IOError:
return err("sqlite: cannot create database directory")
checkErr sqlite3_open_v2(path, addr env.val, flags.cint, nil)
template prepare(q: string, cleanup: untyped): ptr sqlite3_stmt =
var s: ptr sqlite3_stmt
checkErr sqlite3_prepare_v2(env.val, q, q.len.cint, addr s, nil):
cleanup
s
template checkExec(s: ptr sqlite3_stmt) =
if (let x = sqlite3_step(s); x != SQLITE_DONE):
discard sqlite3_finalize(s)
return err($sqlite3_errstr(x))
if (let x = sqlite3_finalize(s); x != SQLITE_OK):
return err($sqlite3_errstr(x))
template checkExec(q: string) =
let s = prepare(q): discard
checkExec(s)
template checkWalPragmaResult(journalModePragma: ptr sqlite3_stmt) =
if (let x = sqlite3_step(journalModePragma); x != SQLITE_ROW):
discard sqlite3_finalize(journalModePragma)
return err($sqlite3_errstr(x))
if (let x = sqlite3_column_type(journalModePragma, 0); x != SQLITE3_TEXT):
discard sqlite3_finalize(journalModePragma)
return err($sqlite3_errstr(x))
if (let x = sqlite3_column_text(journalModePragma, 0);
x != "memory" and x != "wal"):
discard sqlite3_finalize(journalModePragma)
return err("Invalid pragma result: " & $x)
let journalModePragma = prepare("PRAGMA journal_mode = WAL;"): discard
checkWalPragmaResult(journalModePragma)
checkExec(journalModePragma)
ok(SqliteDatabase(env: env.release))
template prepare*(env: Sqlite, q: string, cleanup: untyped): ptr sqlite3_stmt =
var s: ptr sqlite3_stmt
checkErr sqlite3_prepare_v2(env, q, q.len.cint, addr s, nil):
cleanup
s
proc bindParam*(s: RawStmtPtr, n: int, val: auto): cint =
when val is openarray[byte]|seq[byte]:
# The constant, SQLITE_TRANSIENT, may be passed to indicate that the object is to be copied
# prior to the return from sqlite3_bind_*(). The object and pointer to it must remain valid
# until then. SQLite will then manage the lifetime of its private copy.
#
# From: https://www.sqlite.org/c3ref/bind_blob.html
if val.len > 0:
sqlite3_bind_blob(s, n.cint, unsafeAddr val[0], val.len.cint, SQLITE_TRANSIENT)
else:
sqlite3_bind_blob(s, n.cint, nil, 0.cint, SQLITE_TRANSIENT)
elif val is int32:
sqlite3_bind_int(s, n.cint, val)
elif val is uint32:
sqlite3_bind_int64(s, n.cint, val)
elif val is int64:
sqlite3_bind_int64(s, n.cint, val)
elif val is float64:
sqlite3_bind_double(s, n.cint, val)
# Note: bind_text not yet supported in sqlite3_abi wrapper
# elif val is string:
# sqlite3_bind_text(s, n.cint, val.cstring, -1, nil) # `-1` implies string length is the number of bytes up to the first null-terminator
else:
{.fatal: "Please add support for the '" & $typeof(val) & "' type".}
template bindParams(s: RawStmtPtr, params: auto) =
when params is tuple:
var i = 1
for param in fields(params):
checkErr bindParam(s, i, param)
inc i
else:
checkErr bindParam(s, 1, params)
proc exec*[P](s: SqliteStmt[P, void], params: P): DatabaseResult[void] =
let s = RawStmtPtr s
bindParams(s, params)
let res =
if (let v = sqlite3_step(s); v != SQLITE_DONE):
err($sqlite3_errstr(v))
else:
ok()
# release implict transaction
discard sqlite3_reset(s) # same return information as step
discard sqlite3_clear_bindings(s) # no errors possible
res
template readResult(s: RawStmtPtr, column: cint, T: type): auto =
when T is Option:
if sqlite3_column_type(s, column) == SQLITE_NULL:
none(typeof(default(T).get()))
else:
some(readSimpleResult(s, column, typeof(default(T).get())))
else:
readSimpleResult(s, column, T)
template readResult(s: RawStmtPtr, T: type): auto =
when T is tuple:
var res: T
var i = cint 0
for field in fields(res):
field = readResult(s, i, typeof(field))
inc i
res
else:
readResult(s, 0.cint, T)
proc exec*[Params, Res](s: SqliteStmt[Params, Res],
params: Params,
onData: DataProc): DatabaseResult[bool] =
let s = RawStmtPtr s
bindParams(s, params)
try:
var gotResults = false
while true:
let v = sqlite3_step(s)
case v
of SQLITE_ROW:
onData(s)
gotResults = true
of SQLITE_DONE:
break
else:
return err($sqlite3_errstr(v))
return ok gotResults
finally:
# release implicit transaction
discard sqlite3_reset(s) # same return information as step
discard sqlite3_clear_bindings(s) # no errors possible
proc query*(db: SqliteDatabase, query: string, onData: DataProc):
DatabaseResult[bool] =
var s = prepare(db.env, query): discard
try:
var gotResults = false
while true:
let v = sqlite3_step(s)
case v
of SQLITE_ROW:
onData(s)
gotResults = true
of SQLITE_DONE:
break
else:
return err($sqlite3_errstr(v))
return ok gotResults
finally:
# release implicit transaction
discard sqlite3_reset(s) # same return information as step
discard sqlite3_clear_bindings(s) # no errors possible
discard sqlite3_finalize(s) # NB: dispose of the prepared query statement and free associated memory
proc prepareStmt*(
db: SqliteDatabase,
stmt: string,
Params: type,
Res: type
): DatabaseResult[SqliteStmt[Params, Res]] =
var s: RawStmtPtr
checkErr sqlite3_prepare_v2(db.env, stmt, stmt.len.cint, addr s, nil)
ok SqliteStmt[Params, Res](s)
proc close*(db: SqliteDatabase) =
discard sqlite3_close(db.env)
db[] = SqliteDatabase()[]
## Maintenance procedures
# TODO: Cache this value in the SqliteDatabase object.
# Page size should not change during the node execution time
proc getPageSize*(db: SqliteDatabase): DatabaseResult[int64] =
## Query or set the page size of the database. The page size must be a power of
## two between 512 and 65536 inclusive.
var size: int64
proc handler(s: RawStmtPtr) =
size = sqlite3_column_int64(s, 0)
let res = db.query("PRAGMA page_size;", handler)
if res.isErr():
return err("failed to get page_size")
return ok(size)
proc getFreelistCount*(db: SqliteDatabase): DatabaseResult[int64] =
## Return the number of unused pages in the database file.
var count: int64
proc handler(s: RawStmtPtr) =
count = sqlite3_column_int64(s, 0)
let res = db.query("PRAGMA freelist_count;", handler)
if res.isErr():
return err("failed to get freelist_count")
return ok(count)
proc getPageCount*(db: SqliteDatabase): DatabaseResult[int64] =
## Return the total number of pages in the database file.
var count: int64
proc handler(s: RawStmtPtr) =
count = sqlite3_column_int64(s, 0)
let res = db.query("PRAGMA page_count;", handler)
if res.isErr():
return err("failed to get page_count")
return ok(count)
proc gatherSqlitePageStats*(db: SqliteDatabase):
DatabaseResult[(int64, int64, int64)] =
let
pageSize = ?db.getPageSize()
pageCount = ?db.getPageCount()
freelistCount = ?db.getFreelistCount()
return ok((pageSize, pageCount, freelistCount))
proc vacuum*(db: SqliteDatabase): DatabaseResult[void] =
## The VACUUM command rebuilds the database file, repacking it into a minimal amount of disk space.
let res = db.query("VACUUM;", NoopRowHandler)
if res.isErr():
return err("vacuum failed")
return ok()
## Database scheme versioning
proc getUserVersion*(database: SqliteDatabase): DatabaseResult[int64] =
## Get the value of the user-version integer.
##
## The user-version is an integer that is available to applications to use however they want.
## SQLite makes no use of the user-version itself. This integer is stored at offset 60 in
## the database header.
##
## For more info check: https://www.sqlite.org/pragma.html#pragma_user_version
var version: int64
proc handler(s: ptr sqlite3_stmt) =
version = sqlite3_column_int64(s, 0)
let res = database.query("PRAGMA user_version;", handler)
if res.isErr():
return err("failed to get user_version")
ok(version)
proc setUserVersion*(database: SqliteDatabase, version: int64):
DatabaseResult[void] =
## Set the value of the user-version integer.
##
## The user-version is an integer that is available to applications to use however they want.
## SQLite makes no use of the user-version itself. This integer is stored at offset 60 in
## the database header.
##
## For more info check: https://www.sqlite.org/pragma.html#pragma_user_version
let query = "PRAGMA user_version=" & $version & ";"
let res = database.query(query, NoopRowHandler)
if res.isErr():
return err("failed to set user_version")
ok()
## Migration scripts
proc getMigrationScriptVersion(path: string): DatabaseResult[int64] =
let name = extractFilename(path)
let parts = name.split("_", 1)
try:
let version = parseInt(parts[0])
return ok(version)
except ValueError:
return err("failed to parse file version: " & name)
proc isSqlScript(path: string): bool =
path.toLower().endsWith(".sql")
proc listSqlScripts(path: string): DatabaseResult[seq[string]] =
var scripts = newSeq[string]()
try:
for scriptPath in walkDirRec(path):
if isSqlScript(scriptPath):
scripts.add(scriptPath)
else:
debug "invalid migration script", file=scriptPath
except OSError:
return err("failed to list migration scripts: " & getCurrentExceptionMsg())
ok(scripts)
proc filterMigrationScripts(paths: seq[string],
lowVersion, highVersion: int64,
direction: string = "up"):
seq[string] =
## Returns migration scripts whose version fall between lowVersion and highVersion (inclusive)
let filterPredicate = proc(script: string): bool =
if not isSqlScript(script):
return false
if direction != "" and not script.toLower().endsWith("." & direction & ".sql"):
return false
let scriptVersionRes = getMigrationScriptVersion(script)
if scriptVersionRes.isErr():
return false
let scriptVersion = scriptVersionRes.value
return lowVersion < scriptVersion and scriptVersion <= highVersion
paths.filter(filterPredicate)
proc sortMigrationScripts(paths: seq[string]): seq[string] =
## Sort migration scripts paths alphabetically
paths.sorted(system.cmp[string])
proc loadMigrationScripts(paths: seq[string]): DatabaseResult[seq[string]] =
var loadedScripts = newSeq[string]()
for script in paths:
try:
loadedScripts.add(readFile(script))
except OSError, IOError:
return err("failed to load script '" & script & "': " & getCurrentExceptionMsg())
ok(loadedScripts)
proc breakIntoStatements(script: string): seq[string] =
var statements = newSeq[string]()
for chunk in script.split(';'):
if chunk.strip().isEmptyOrWhitespace():
continue
let statement = chunk.strip() & ";"
statements.add(statement)
statements
proc migrate*(db: SqliteDatabase,
targetVersion: int64,
migrationsScriptsDir: string):
DatabaseResult[void] =
## Compares the `user_version` of the sqlite database with the provided `targetVersion`, then
## it runs migration scripts if the `user_version` is outdated. The `migrationScriptsDir` path
## points to the directory holding the migrations scripts once the db is updated, it sets the
## `user_version` to the `tragetVersion`.
##
## NOTE: Down migration it is not currently supported
let userVersion = ?db.getUserVersion()
if userVersion == targetVersion:
debug "database schema is up to date", userVersion=userVersion, targetVersion=targetVersion
return ok()
info "database schema is outdated", userVersion=userVersion, targetVersion=targetVersion
# Load migration scripts
var migrationScriptsPaths = ?listSqlScripts(migrationsScriptsDir)
migrationScriptsPaths = filterMigrationScripts(migrationScriptsPaths, lowVersion=userVersion, highVersion=targetVersion, direction="up")
migrationScriptsPaths = sortMigrationScripts(migrationScriptsPaths)
if migrationScriptsPaths.len <= 0:
debug "no scripts to be run"
return ok()
let scripts = ?loadMigrationScripts(migrationScriptsPaths)
# Run the migration scripts
for script in scripts:
for statement in script.breakIntoStatements():
debug "executing migration statement", statement=statement
let execRes = db.query(statement, NoopRowHandler)
if execRes.isErr():
error "failed to execute migration statement", statement=statement, error=execRes.error
return err("failed to execute migration statement")
debug "migration statement executed succesfully", statement=statement
# Update user_version
?db.setUserVersion(targetVersion)
debug "database user_version updated", userVersion=targetVersion
ok()
proc performSqliteVacuum*(db: SqliteDatabase): DatabaseResult[void] =
## SQLite database vacuuming
# TODO: Run vacuuming conditionally based on database page stats
# if (pageCount > 0 and freelistCount > 0):
debug "starting sqlite database vacuuming"
let resVacuum = db.vacuum()
if resVacuum.isErr():
return err("failed to execute vacuum: " & resVacuum.error)
debug "finished sqlite database vacuuming"
ok()