/* 2022-05-22 The author disclaims copyright to this source code. In place of a legal notice, here is a blessing: * May you do good and not evil. * May you find forgiveness for yourself and forgive others. * May you share freely, never taking more than you give. *********************************************************************** This file is intended to be appended to the emcc-generated sqlite3.js via emcc: emcc ... -sMODULARIZE -sEXPORT_NAME=initSqlite3Module --post-js=THIS_FILE It is loaded by importing the emcc-generated sqlite3.js, then: initSqlite3Module({module object}).then( function(theModule){ theModule.sqlite3 == an object containing this file's deliverables: { api: bindings for much of the core sqlite3 APIs, SQLite3: high-level OO API wrapper } }); It is up to the caller to provide a module object compatible with emcc, but it can be a plain empty object. The object passed to initSqlite3Module() will get populated by the emscripten-generated bits and, in part, by the code from this file. Specifically, this file installs the `theModule.sqlite3` part shown above. The resulting sqlite3.api object wraps the standard sqlite3 C API in a way as close to its native form as JS allows for. The sqlite3.SQLite3 object provides a higher-level wrapper more appropriate for general client-side use in JS. Because using certain parts of the low-level API properly requires some degree of WASM-related magic, it is not recommended that that API be used as-is in client-level code. Rather, client code should use the higher-level OO API or write a custom wrapper on top of the lower-level API. In short, most of the C-style API is used in an intuitive manner from JS but any C-style APIs which take pointers-to-pointer arguments require WASM-specific interfaces installed by emcscripten-generated code. Those which take or return only integers, doubles, strings, or "plain" pointers to db or statement objects can be used in "as normal," noting that "pointers" in wasm are simply 32-bit integers. # Goals and Non-goals of this API Goals: - Except where noted in the non-goals, provide a more-or-less complete wrapper to the sqlite3 C API, insofar as WASM feature parity with C allows for. In fact, provide at least 3... - (1) The aforementioned C-style API. (2) An OO-style API on top of that, designed to run in the same thread (main window or Web Worker) as the C API. (3) A less-capable wrapper which can work across the main window/worker boundary, where the sqlite3 API is one of those and this wrapper is in the other. That constellation places some considerable limitations on how the API can be interacted with, but keeping the DB operations out of the UI thread is generally desirable. - Insofar as possible, support client-side storage using JS filesystem APIs. As of this writing, such things are still very much TODO. Non-goals: - As WASM is a web-centric technology and UTF-8 is the King of Encodings in that realm, there are no current plans to support the UTF16-related APIs. They would add a complication to the bindings for no appreciable benefit. - Supporting old or niche-market platforms. WASM is built for a modern web and requires modern platforms. */ if(!Module.postRun) Module.postRun = []; /* ^^^^ the name Module is, in this setup, scope-local in the generated file sqlite3.js, with which this file gets combined at build-time. */ Module.postRun.push(function(namespace){ 'use strict'; /* For reference: sql.js does essentially everything we want and it solves much of the wasm-related voodoo, but we'll need a different structure because we want the db connection to run in a worker thread and feed data back into the main thread. Regardless of those differences, it makes a great point of reference: https://github.com/sql-js/sql.js Some of the specific design goals here: - Bind a low-level sqlite3 API which is close to the native one in terms of usage. - Create a higher-level one, more akin to sql.js and node.js-style implementations. This one would speak directly to the low-level API. This API could be used by clients who import the low-level API directly into their main thread (which we don't want to recommend but also don't want to outright forbid). - Create a second higher-level one which speaks to the low-level API via worker messages. This one would be intended for use in the main thread, talking to the low-level UI via worker messages. Because workers have only a single message channel, some acrobatics will be needed here to feed async work results back into client-side callbacks (as those callbacks cannot simply be passed to the worker). Exactly what those acrobatics should look like is not yet entirely clear and much experimentation is pending. */ const SQM = namespace/*the sqlite module object */; /** Set up the main sqlite3 binding API here, mimicking the C API as closely as we can. Attribution: though not a direct copy/paste, much of what follows is strongly influenced by the sql.js implementation. */ const api = { /* It is important that the following integer values match those from the C code. Ideally we could fetch them from the C API, e.g., in the form of a JSON object, but getting that JSON string constructed within our current confines is currently not worth the effort. Reminder to self: we could probably do so by adding the proverbial level of indirection, calling in to C to get it, and having that C func call an emscripten-installed/JS-implemented library function which builds the result object: const obj = {}; sqlite3__get_enum(function(key,val){ obj[key] = val; }); but whether or not we can pass a function that way, via a (void*) is as yet unknown. */ /* Minimum subset of sqlite result codes we'll need. */ SQLITE_OK: 0, SQLITE_ROW: 100, SQLITE_DONE: 101, /* sqlite data types */ SQLITE_INTEGER: 1, SQLITE_FLOAT: 2, SQLITE_TEXT: 3, SQLITE_BLOB: 4, SQLITE_NULL: 5, /* create_function() flags */ SQLITE_DETERMINISTIC: 0x000000800, SQLITE_DIRECTONLY: 0x000080000, SQLITE_INNOCUOUS: 0x000200000, /* sqlite encodings, used for creating UDFs, noting that we will only support UTF8. */ SQLITE_UTF8: 1 }; const cwrap = SQM.cwrap; [/* C-side functions to bind. Each entry is an array with 3 or 4 elements: ["c-side name", "result type" (cwrap() syntax), [arg types in cwrap() syntax] ] If it has 4 elements, the first one is an alternate name to use for the JS-side binding. That's required when overloading a binding for two different uses. */ ["sqlite3_bind_blob","number",["number", "number", "number", "number", "number"]], ["sqlite3_bind_double","number",["number", "number", "number"]], ["sqlite3_bind_int","number",["number", "number", "number"]], /*Noting that JS/wasm combo does not currently support 64-bit integers: ["sqlite3_bind_int64","number",["number", "number", "number"]],*/ ["sqlite3_bind_null","void",["number"]], ["sqlite3_bind_parameter_count", "number", ["number"]], ["sqlite3_bind_parameter_index","number",["number", "string"]], ["sqlite3_bind_text","number",["number", "number", "number", "number", "number"]], ["sqlite3_changes", "number", ["number"]], ["sqlite3_clear_bindings","number",["number"]], ["sqlite3_close_v2", "number", ["number"]], ["sqlite3_column_blob","number", ["number", "number"]], ["sqlite3_column_bytes","number",["number", "number"]], ["sqlite3_column_count", "number", ["number"]], ["sqlite3_column_count","number",["number"]], ["sqlite3_column_double","number",["number", "number"]], ["sqlite3_column_int","number",["number", "number"]], /*Noting that JS/wasm combo does not currently support 64-bit integers: ["sqlite3_column_int64","number",["number", "number"]],*/ ["sqlite3_column_name","string",["number", "number"]], ["sqlite3_column_text","string",["number", "number"]], ["sqlite3_column_type","number",["number", "number"]], ["sqlite3_compileoption_get", "string", ["number"]], ["sqlite3_compileoption_used", "number", ["string"]], ["sqlite3_create_function_v2", "number", ["number", "string", "number", "number","number", "number", "number", "number", "number"]], ["sqlite3_data_count", "number", ["number"]], ["sqlite3_db_filename", "string", ["number", "string"]], ["sqlite3_errmsg", "string", ["number"]], ["sqlite3_exec", "number", ["number", "string", "number", "number", "number"]], ["sqlite3_finalize", "number", ["number"]], ["sqlite3_interrupt", "void", ["number"]], ["sqlite3_libversion", "string", []], ["sqlite3_open", "number", ["string", "number"]], //["sqlite3_open_v2", "number", ["string", "number", "number", "string"]], //^^^^ TODO: add the flags needed for the 3rd arg ["sqlite3_prepare_v2", "number", ["number", "string", "number", "number", "number"]], ["sqlite3_prepare_v2_sqlptr", "sqlite3_prepare_v2", /* Impl which requires that the 2nd argument be a pointer to the SQL, instead of a string. This is used for cases where we require a non-NULL value for the final argument. We may or may not need this, depending on how our higher-level API shapes up, but this code's spiritual guide (sql.js) uses it we we'll include it. */ "number", ["number", "number", "number", "number", "number"]], ["sqlite3_reset", "number", ["number"]], ["sqlite3_result_blob",null,["number", "number", "number", "number"]], ["sqlite3_result_double",null,["number", "number"]], ["sqlite3_result_error",null,["number", "string", "number"]], ["sqlite3_result_int",null,["number", "number"]], ["sqlite3_result_null",null,["number"]], ["sqlite3_result_text",null,["number", "string", "number", "number"]], ["sqlite3_sourceid", "string", []], ["sqlite3_sql", "string", ["number"]], ["sqlite3_step", "number", ["number"]], ["sqlite3_value_blob", "number", ["number"]], ["sqlite3_value_bytes","number",["number"]], ["sqlite3_value_double","number",["number"]], ["sqlite3_value_text", "string", ["number"]], ["sqlite3_value_type", "number", ["number"]] //["sqlite3_normalized_sql", "string", ["number"]] ].forEach(function(a){ const k = (4==a.length) ? a.shift() : a[0]; api[k] = cwrap.apply(this, a); }); /* What follows is colloquially known as "OO API #1". It is a binding of the sqlite3 API which is designed to be run within the same thread (main or worker) as the one in which the sqlite3 WASM binding was initialized. This wrapper cannot use the sqlite3 binding if, e.g., the wrapper is in the main thread and the sqlite3 API is in a worker. */ /** Memory for use in some pointer-to-pointer-passing routines. */ const pPtrArg = stackAlloc(4); /** Throws a new error, concatenating all args with a space between each. */ const toss = function(){ throw new Error(Array.prototype.join.call(arguments, ' ')); }; /** The DB class wraps a sqlite3 db handle. It accepts the following argument signatures: - () - (undefined) (same effect as ()) - (Uint8Array holding an sqlite3 db image) It always generates a random filename and sets is to the `filename` property of this object. Developer's note: the reason it does not (any longer) support ":memory:" as a name is because we can apparently only export images of DBs which are stored in the pseudo-filesystem provided by the JS APIs. Since exporting and importing images is an important usability feature for this class, ":memory:" DBs are not supported (until/unless we can find a way to export those as well). The naming semantics will certainly evolve as this API does. */ const DB = function(arg){ const fn = "db-"+((Math.random() * 10000000) | 0)+ "-"+((Math.random() * 10000000) | 0)+".sqlite3"; let buffer; if(name instanceof Uint8Array){ buffer = arg; arg = undefined; }else if(arguments.length && undefined!==arg){ toss("Invalid arguments to DB constructor.", "Expecting no args, undefined, or a", "sqlite3 file as a Uint8Array."); } if(buffer){ FS.createDataFile("/", fn, buffer, true, true); } setValue(pPtrArg, 0, "i32"); this.checkRc(api.sqlite3_open(fn, pPtrArg)); this._pDb = getValue(pPtrArg, "i32"); this.filename = fn; this._statements = {/*map of open Stmt _pointers_ to Stmt*/}; this._udfs = {/*map of UDF names to wasm function _pointers_*/}; }; /** Internal-use enum for mapping JS types to DB-bindable types. These do not (and need not) line up with the SQLITE_type values. All values in this enum must be truthy and distinct but they need not be numbers. */ const BindTypes = { null: 1, number: 2, string: 3, boolean: 4, blob: 5 }; BindTypes['undefined'] == BindTypes.null; /** This class wraps sqlite3_stmt. Calling this constructor directly will trigger an exception. Use DB.prepare() to create new instances. */ const Stmt = function(){ if(BindTypes!==arguments[2]){ toss("Do not call the Stmt constructor directly. Use DB.prepare()."); } this.db = arguments[0]; this._pStmt = arguments[1]; this.columnCount = api.sqlite3_column_count(this._pStmt); this.parameterCount = api.sqlite3_bind_parameter_count(this._pStmt); this._allocs = [/*list of alloc'd memory blocks for bind() values*/] }; /** Throws if the given DB has been closed, else it is returned. */ const affirmDbOpen = function(db){ if(!db._pDb) toss("DB has been closed."); return db; }; /** Returns true if n is a 32-bit (signed) integer, else false. */ const isInt32 = function(n){ return (n===n|0 && n<0xFFFFFFFF) ? true : undefined; }; /** Expects to be passed (arguments) from DB.exec() and DB.execMulti(). Does the argument processing/validation, throws on error, and returns a new object on success: { sql: the SQL, obt: optionsObj, cbArg: function} cbArg is only set if the opt.callback is set, in which case it's a function which expects to be passed the current Stmt and returns the callback argument of the type indicated by the input arguments. */ const parseExecArgs = function(args){ const out = {}; switch(args.length){ case 1: if('string'===typeof args[0]){ out.sql = args[0]; out.opt = {}; }else if(args[0] && 'object'===typeof args[0]){ out.opt = args[0]; out.sql = out.opt.sql; } break; case 2: out.sql = args[0]; out.opt = args[1]; break; default: toss("Invalid argument count for exec()."); }; if('string'!==typeof out.sql) toss("Missing SQL argument."); if(out.opt.callback){ switch((undefined===out.opt.rowMode) ? 'stmt' : out.opt.rowMode) { case 'object': out.cbArg = (stmt)=>stmt.get({}); break; case 'array': out.cbArg = (stmt)=>stmt.get([]); break; case 'stmt': out.cbArg = (stmt)=>stmt; break; default: toss("Invalid rowMode:",out.opt.rowMode); } } return out; }; /** If object opts has _its own_ property named p then that property's value is returned, else dflt is returned. */ const getOwnOption = (opts, p, dflt)=> opts.hasOwnProperty(p) ? opts[p] : dflt; DB.prototype = { /** Expects to be given an sqlite3 API result code. If it is falsy, this function returns this object, else it throws an exception with an error message from sqlite3_errmsg(), using this object's db handle. Note that if it's passed a non-error code like SQLITE_ROW or SQLITE_DONE, it will still throw but the error string might be "Not an error." The various non-0 non-error codes need to be checked for in client code where they are expected. */ checkRc: function(sqliteResultCode){ if(!sqliteResultCode) return this; toss("sqlite result code",sqliteResultCode+":", api.sqlite3_errmsg(this._pDb) || "Unknown db error."); }, /** Finalizes all open statements and closes this database connection. This is a no-op if the db has already been closed. */ close: function(){ if(this._pDb){ let s; const that = this; Object.keys(this._statements).forEach(function(k,s){ delete that._statements[k]; if(s && s._pStmt) s.finalize(); }); Object.values(this._udfs).forEach(SQM.removeFunction); delete this._udfs; delete this._statements; delete this.filename; api.sqlite3_close_v2(this._pDb); delete this._pDb; } }, /** Similar to this.filename but will return NULL for special names like ":memory:". Not of much use until we have filesystem support. Throws if the DB has been closed. If passed an argument it then it will return the filename of the ATTACHEd db with that name, else it assumes a name of `main`. */ fileName: function(dbName){ return api.sqlite3_db_filename(affirmDbOpen(this)._pDb, dbName||"main"); }, /** Compiles the given SQL and returns a prepared Stmt. This is the only way to create new Stmt objects. Throws on error. */ prepare: function(sql){ affirmDbOpen(this); setValue(pPtrArg,0,"i32"); this.checkRc(api.sqlite3_prepare_v2(this._pDb, sql, -1, pPtrArg, null)); const pStmt = getValue(pPtrArg, "i32"); if(!pStmt) toss("Empty SQL is not permitted."); const stmt = new Stmt(this, pStmt, BindTypes); this._statements[pStmt] = stmt; return stmt; }, /** This function works like execMulti(), and takes the same arguments, but is more efficient (performs much less work) when the input SQL is only a single statement. If passed a multi-statement SQL, it only processes the first one. This function supports one additional option not used by execMulti(): - .multi: if true, this function acts as a proxy for execMulti(). */ exec: function(/*(sql [,optionsObj]) or (optionsObj)*/){ affirmDbOpen(this); const arg = parseExecArgs(arguments); if(!arg.sql) return this; else if(arg.opt.multi){ return this.execMulti(arg, undefined, BindTypes); } const opt = arg.opt; let stmt; try { stmt = this.prepare(arg.sql); if(opt.bind) stmt.bind(opt.bind); if(opt.callback){ while(stmt.step()){ stmt._isLocked = true; opt.callback(arg.cbArg(stmt), stmt); stmt._isLocked = false; } }else{ stmt.step(); } }finally{ if(stmt){ delete stmt._isLocked; stmt.finalize(); } } return this; }/*exec()*/, /** Executes one or more SQL statements. Its arguments must be either (sql,optionsObject) or (optionsObject). In the latter case, optionsObject.sql must contain the SQL to execute. Returns this object. Throws on error. If no SQL is provided, or a non-string is provided, an exception is triggered. Empty SQL, on the other hand, is simply a no-op. The optional options object may contain any of the following properties: - .sql = the SQL to run (unless it's provided as the first argument). - .bind = a single value valid as an argument for Stmt.bind(). This is ONLY applied to the FIRST non-empty statement in the SQL which has any bindable parameters. (Empty statements are skipped entirely.) - .callback = a function which gets called for each row of the FIRST statement in the SQL (if it has any result rows). The second argument passed to the callback is always the current Stmt object (so that the caller may collect column names, or similar). The first argument passed to the callback defaults to the current Stmt object but may be changed with ... - .rowMode = a string describing what type of argument should be passed as the first argument to the callback. A value of 'object' causes the results of `stmt.get({})` to be passed to the object. A value of 'array' causes the results of `stmt.get([])` to be passed to the callback. A value of 'stmt' is equivalent to the default, passing the current Stmt to the callback (noting that it's always passed as the 2nd argument). Any other value triggers an exception. - saveSql = an optional array. If set, the SQL of each executed statement is appended to this array before the statement is executed (but after it is prepared - we don't have the string until after that). Empty SQL statements are elided. ACHTUNG #1: The callback MUST NOT modify the Stmt object. Calling any of the Stmt.get() variants, Stmt.getColumnName(), or simililar, is legal, but calling step() or finalize() is not. Routines which are illegal in this context will trigger an exception. ACHTUNG #2: The semantics of the `bind` and `callback` options may well change or those options may be removed altogether for this function (but retained for exec()). */ execMulti: function(/*(sql [,obj]) || (obj)*/){ affirmDbOpen(this); const arg = (BindTypes===arguments[2] /* ^^^ Being passed on from exec() */ ? arguments[0] : parseExecArgs(arguments)); if(!arg.sql) return this; const opt = arg.opt; const stack = stackSave(); let stmt; let bind = opt.bind; let rowMode = ( (opt.callback && opt.rowMode) ? opt.rowMode : false); try{ let pSql = SQM.allocateUTF8OnStack(arg.sql) const pzTail = stackAlloc(4); while(getValue(pSql, "i8")){ setValue(pPtrArg, 0, "i32"); setValue(pzTail, 0, "i32"); this.checkRc(api.sqlite3_prepare_v2_sqlptr( this._pDb, pSql, -1, pPtrArg, pzTail )); const pStmt = getValue(pPtrArg, "i32"); pSql = getValue(pzTail, "i32"); if(!pStmt) continue; if(opt.saveSql){ opt.saveSql.push(api.sqlite3_sql(pStmt).trim()); } stmt = new Stmt(this, pStmt, BindTypes); if(bind && stmt.parameterCount){ stmt.bind(bind); bind = null; } if(opt.callback && null!==rowMode){ while(stmt.step()){ stmt._isLocked = true; callback(arg.cbArg(stmt), stmt); stmt._isLocked = false; } rowMode = null; }else{ // Do we need to while(stmt.step()){} here? stmt.step(); } stmt.finalize(); stmt = null; } }finally{ if(stmt){ delete stmt._isLocked; stmt.finalize(); } stackRestore(stack); } return this; }/*execMulti()*/, /** Creates a new scalar UDF (User-Defined Function) which is accessible via SQL code. This function may be called in any of the following forms: - (name, function) - (name, function, optionsObject) - (name, optionsObject) - (optionsObject) In the final two cases, the function must be defined as the 'callback' property of the options object. In the final case, the function's name must be the 'name' property. This can only be used to create scalar functions, not aggregate or window functions. UDFs cannot be removed from a DB handle after they're added. On success, returns this object. Throws on error. When called from SQL, arguments to the UDF, and its result, will be converted between JS and SQL with as much fidelity as is feasible, triggering an exception if a type conversion cannot be determined. Some freedom is afforded to numeric conversions due to friction between the JS and C worlds: integers which are larger than 32 bits will be treated as doubles, as JS does not support 64-bit integers and it is (as of this writing) illegal to use WASM functions which take or return 64-bit integers from JS. The optional options object may contain flags to modify how the function is defined: - .arity: the number of arguments which SQL calls to this function expect or require. The default value is the callback's length property (i.e. the number of declared parameters it has). A value of -1 means that the function is variadic and may accept any number of arguments, up to sqlite3's compile-time limits. sqlite3 will enforce the argument count if is zero or greater. The following properties correspond to flags documented at: https://sqlite.org/c3ref/create_function.html - .deterministic = SQLITE_DETERMINISTIC - .directOnly = SQLITE_DIRECTONLY - .innocuous = SQLITE_INNOCUOUS Maintenance reminder: the ability to add new WASM-accessible functions to the runtime requires that the WASM build is compiled with emcc's `-sALLOW_TABLE_GROWTH` flag. */ createFunction: function f(name, callback,opt){ switch(arguments.length){ case 1: /* (optionsObject) */ opt = name; name = opt.name; callback = opt.callback; break; case 2: /* (name, callback|optionsObject) */ if(!(callback instanceof Function)){ opt = callback; callback = opt.callback; } break; default: break; } if(!opt) opt = {}; if(!(callback instanceof Function)){ toss("Invalid arguments: expecting a callback function."); }else if('string' !== typeof name){ toss("Invalid arguments: missing function name."); } if(!f._extractArgs){ /* Static init */ f._extractArgs = function(argc, pArgv){ let i, pVal, valType, arg; const tgt = []; for(i = 0; i < argc; ++i){ pVal = getValue(pArgv + (4 * i), "i32"); valType = api.sqlite3_value_type(pVal); switch(valType){ case api.SQLITE_INTEGER: case api.SQLITE_FLOAT: arg = api.sqlite3_value_double(pVal); break; case SQLITE_TEXT: arg = api.sqlite3_value_text(pVal); break; case SQLITE_BLOB:{ const n = api.sqlite3_value_bytes(ptr); const pBlob = api.sqlite3_value_blob(ptr); arg = new Uint8Array(n); let i; for(i = 0; i < n; ++i) arg[i] = HEAP8[pBlob+i]; break; } default: arg = null; break; } tgt.push(arg); } return tgt; }/*_extractArgs()*/; f._setResult = function(pCx, val){ switch(typeof val) { case 'boolean': api.sqlite3_result_int(pCx, val ? 1 : 0); break; case 'number': { (isInt32(val) ? api.sqlite3_result_int : api.sqlite3_result_double)(pCx, val); break; } case 'string': api.sqlite3_result_text(pCx, val, -1, -1/*==SQLITE_TRANSIENT*/); break; case 'object': if(null===val) { api.sqlite3_result_null(pCx); break; }else if(undefined!==val.length){ const pBlob = SQM.allocate(val, SQM.ALLOC_NORMAL); api.sqlite3_result_blob(pCx, pBlob, val.length, -1/*==SQLITE_TRANSIENT*/); SQM._free(blobptr); break; } // else fall through default: toss("Don't not how to handle this UDF result value:",val); }; }/*_setResult()*/; }/*static init*/ const wrapper = function(pCx, argc, pArgv){ try{ f._setResult(pCx, callback.apply(null, f._extractArgs(argc, pArgv))); }catch(e){ api.sqlite3_result_error(pCx, e.message, -1); } }; const pUdf = SQM.addFunction(wrapper, "viii"); let fFlags = 0; if(getOwnOption(opt, 'deterministic')) fFlags |= api.SQLITE_DETERMINISTIC; if(getOwnOption(opt, 'directOnly')) fFlags |= api.SQLITE_DIRECTONLY; if(getOwnOption(opt, 'innocuous')) fFlags |= api.SQLITE_INNOCUOUS; name = name.toLowerCase(); try { this.checkRc(api.sqlite3_create_function_v2( this._pDb, name, (opt.hasOwnProperty('arity') ? +opt.arity : callback.length), api.SQLITE_UTF8 | fFlags, null/*pApp*/, pUdf, null/*xStep*/, null/*xFinal*/, null/*xDestroy*/)); }catch(e){ SQM.removeFunction(pUdf); throw e; } if(this._udfs.hasOwnProperty(name)){ SQM.removeFunction(this._udfs[name]); } this._udfs[name] = pUdf; return this; }/*createFunction()*/, /** Prepares the given SQL, step()s it one time, and returns the value of the first result column. If it has no results, undefined is returned. If passed a second argument, it is treated like an argument to Stmt.bind(), so may be any type supported by that function. Throws on error (e.g. malformed SQL). */ selectValue: function(sql,bind){ let stmt, rc; try { stmt = this.prepare(sql).bind(bind); if(stmt.step()) rc = stmt.get(0); }finally{ if(stmt) stmt.finalize(); } return rc; }, /** Exports a copy of this db's file as a Uint8Array and returns it. It is technically not legal to call this while any prepared statement are currently active. Throws if this db is not open. Maintenance reminder: the corresponding sql.js impl of this feature closes the current db, finalizing any active statements and (seemingly unnecessarily) destroys any UDFs, copies the file, and then re-opens it (without restoring the UDFs). Those gymnastics are not necessary on the tested platform but might be necessary on others. Because of that eventuality, this interface currently enforces that no statements are active when this is run. It will throw if any are. */ exportBinaryImage: function(){ affirmDbOpen(this); if(Object.keys(this._statements).length){ toss("Cannot export with prepared statements active!", "finalize() all statements and try again."); } const img = FS.readFile(this.filename, {encoding:"binary"}); return img; } }/*DB.prototype*/; /** Throws if the given Stmt has been finalized, else stmt is returned. */ const affirmStmtOpen = function(stmt){ if(!stmt._pStmt) toss("Stmt has been closed."); return stmt; }; /** Returns an opaque truthy value from the BindTypes enum if v's type is a valid bindable type, else returns a falsy value. As a special case, a value of undefined is treated as a bind type of null. */ const isSupportedBindType = function(v){ let t = BindTypes[(null===v||undefined===v) ? 'null' : typeof v]; switch(t){ case BindTypes.boolean: case BindTypes.null: case BindTypes.number: case BindTypes.string: return t; default: if(v instanceof Uint8Array) return BindTypes.blob; return undefined; } }; /** If isSupportedBindType(v) returns a truthy value, this function returns that value, else it throws. */ const affirmSupportedBindType = function(v){ return isSupportedBindType(v) || toss("Unsupport bind() argument type."); }; /** If key is a number and within range of stmt's bound parameter count, key is returned. If key is not a number then it is checked against named parameters. If a match is found, its index is returned. Else it throws. */ const affirmParamIndex = function(stmt,key){ const n = ('number'===typeof key) ? key : api.sqlite3_bind_parameter_index(stmt._pStmt, key); if(0===n || (n===key && (n!==(n|0)/*floating point*/))){ toss("Invalid bind() parameter name: "+key); } else if(n<1 || n>stmt.parameterCount) toss("Bind index",key,"is out of range."); return n; }; /** Throws if ndx is not an integer or if it is out of range for stmt.columnCount, else returns stmt. Reminder: this will also fail after the statement is finalized but the resulting error will be about an out-of-bounds column index. */ const affirmColIndex = function(stmt,ndx){ if((ndx !== (ndx|0)) || ndx<0 || ndx>=stmt.columnCount){ toss("Column index",ndx,"is out of range."); } return stmt; }; /** If stmt._isLocked is truthy, this throws an exception complaining that the 2nd argument (an operation name, e.g. "bind()") is not legal while the statement is "locked". Locking happens before an exec()-like callback is passed a statement, to ensure that the callback does not mutate or finalize the statement. If it does not throw, it returns stmt. */ const affirmUnlocked = function(stmt,currentOpName){ if(stmt._isLocked){ toss("Operation is illegal when statement is locked:",currentOpName); } return stmt; }; /** Binds a single bound parameter value on the given stmt at the given index (numeric or named) using the given bindType (see the BindTypes enum) and value. Throws on error. Returns stmt on success. */ const bindOne = function f(stmt,ndx,bindType,val){ affirmUnlocked(stmt, 'bind()'); if(!f._){ f._ = { string: function(stmt, ndx, val, asBlob){ const bytes = intArrayFromString(val,true); const pStr = SQM.allocate(bytes, ALLOC_NORMAL); stmt._allocs.push(pStr); const func = asBlob ? api.sqlite3_bind_blob : api.sqlite3_bind_text; return func(stmt._pStmt, ndx, pStr, bytes.length, 0); } }; } affirmSupportedBindType(val); ndx = affirmParamIndex(stmt,ndx); let rc = 0; switch((null===val || undefined===val) ? BindTypes.null : bindType){ case BindTypes.null: rc = api.sqlite3_bind_null(stmt._pStmt, ndx); break; case BindTypes.string:{ rc = f._.string(stmt, ndx, val, false); break; } case BindTypes.number: { const m = (isInt32(val) ? api.sqlite3_bind_int /*It's illegal to bind a 64-bit int from here*/ : api.sqlite3_bind_double); rc = m(stmt._pStmt, ndx, val); break; } case BindTypes.boolean: rc = api.sqlite3_bind_int(stmt._pStmt, ndx, val ? 1 : 0); break; case BindTypes.blob: { if('string'===typeof val){ rc = f._.string(stmt, ndx, val, true); }else{ const len = val.length; if(undefined===len){ toss("Binding a value as a blob requires", "that it have a length member."); } const pBlob = SQM.allocate(val, ALLOC_NORMAL); stmt._allocs.push(pBlob); rc = api.sqlite3_bind_blob(stmt._pStmt, ndx, pBlob, len, 0); } } default: toss("Unsupported bind() argument type."); } if(rc) stmt.db.checkRc(rc); return stmt; }; /** Frees any memory explicitly allocated for the given Stmt object. Returns stmt. */ const freeBindMemory = function(stmt){ let m; while(undefined !== (m = stmt._allocs.pop())){ SQM._free(m); } return stmt; }; Stmt.prototype = { /** "Finalizes" this statement. This is a no-op if the statement has already been finalizes. Returns undefined. Most methods in this class will throw if called after this is. */ finalize: function(){ if(this._pStmt){ affirmUnlocked(this,'finalize()'); freeBindMemory(this); delete this.db._statements[this._pStmt]; api.sqlite3_finalize(this._pStmt); delete this.columnCount; delete this.parameterCount; delete this._pStmt; delete this.db; delete this._isLocked; } }, /** Clears all bound values. Returns this object. Throws if this statement has been finalized. */ clearBindings: function(){ freeBindMemory( affirmUnlocked(affirmStmtOpen(this), 'clearBindings()') ); api.sqlite3_clear_bindings(this._pStmt); this._mayGet = false; return this; }, /** Resets this statement so that it may be step()ed again from the beginning. Returns this object. Throws if this statement has been finalized. If passed a truthy argument then this.clearBindings() is also called, otherwise any existing bindings, along with any memory allocated for them, are retained. */ reset: function(alsoClearBinds){ affirmUnlocked(this,'reset()'); if(alsoClearBinds) this.clearBindings(); api.sqlite3_reset(affirmStmtOpen(this)._pStmt); this._mayGet = false; return this; }, /** Binds one or more values to its bindable parameters. It accepts 1 or 2 arguments: If passed a single argument, it must be either an array, an object, or a value of a bindable type (see below). If passed 2 arguments, the first one is the 1-based bind index or bindable parameter name and the second one must be a value of a bindable type. Bindable value types: - null is bound as NULL. - undefined as a standalone value is a no-op intended to simplify certain client-side use cases: passing undefined as a value to this function will not actually bind anything and this function will skip confirmation that binding is even legal. (Those semantics simplify certain client-side uses.) Conversely, a value of undefined as an array or object property when binding an array/object (see below) is treated the same as null. - Numbers are bound as either doubles or integers: doubles if they are larger than 32 bits, else double or int32, depending on whether they have a fractional part. (It is, as of this writing, illegal to call (from JS) a WASM function which either takes or returns an int64.) Booleans are bound as integer 0 or 1. It is not expected the distinction of binding doubles which have no fractional parts is integers is significant for the majority of clients due to sqlite3's data typing model. This API does not currently support the BigInt type. - Strings are bound as strings (use bindAsBlob() to force blob binding). - Uint8Array instances are bound as blobs. If passed an array, each element of the array is bound at the parameter index equal to the array index plus 1 (because arrays are 0-based but binding is 1-based). If passed an object, each object key is treated as a bindable parameter name. The object keys _must_ match any bindable parameter names, including any `$`, `@`, or `:` prefix. Because `$` is a legal identifier chararacter in JavaScript, that is the suggested prefix for bindable parameters. It returns this object on success and throws on error. Errors include: - Any bind index is out of range, a named bind parameter does not match, or this statement has no bindable parameters. - Any value to bind is of an unsupported type. - Passed no arguments or more than two. - The statement has been finalized. */ bind: function(/*[ndx,] arg*/){ affirmStmtOpen(this); let ndx, arg; switch(arguments.length){ case 1: ndx = 1; arg = arguments[0]; break; case 2: ndx = arguments[0]; arg = arguments[1]; break; default: toss("Invalid bind() arguments."); } if(undefined===arg){ /* It might seem intuitive to bind undefined as NULL but this approach simplifies certain client-side uses when passing on arguments between 2+ levels of functions. */ return this; }else if(!this.parameterCount){ toss("This statement has no bindable parameters."); } this._mayGet = false; if(null===arg){ /* bind NULL */ return bindOne(this, ndx, BindTypes.null, arg); } else if(Array.isArray(arg)){ /* bind each entry by index */ if(1!==arguments.length){ toss("When binding an array, an index argument is not permitted."); } arg.forEach((v,i)=>bindOne(this, i+1, affirmSupportedBindType(v), v)); return this; } else if('object'===typeof arg/*null was checked above*/){ /* bind by name */ if(1!==arguments.length){ toss("When binding an object, an index argument is not permitted."); } Object.keys(arg) .forEach(k=>bindOne(this, k, affirmSupportedBindType(arg[k]), arg[k])); return this; }else{ return bindOne(this, ndx, affirmSupportedBindType(arg), arg); } toss("Should not reach this point."); }, /** Special case of bind() which binds the given value using the BLOB binding mechanism instead of the default selected one for the value. The ndx may be a numbered or named bind index. The value must be of type string, Uint8Array, or null/undefined (both treated as null). If passed a single argument, a bind index of 1 is assumed. */ bindAsBlob: function(ndx,arg){ affirmStmtOpen(this); if(1===arguments.length){ ndx = 1; arg = arguments[0]; } const t = affirmSupportedBindType(arg); if(BindTypes.string !== t && BindTypes.blob !== t && BindTypes.null !== t){ toss("Invalid value type for bindAsBlob()"); } this._mayGet = false; return bindOne(this, ndx, BindTypes.blob, arg); }, /** Steps the statement one time. If the result indicates that a row of data is available, true is returned. If no row of data is available, false is returned. Throws on error. */ step: function(){ affirmUnlocked(this, 'step()'); const rc = api.sqlite3_step(affirmStmtOpen(this)._pStmt); switch(rc){ case api.SQLITE_DONE: return this._mayGet = false; case api.SQLITE_ROW: return this._mayGet = true; default: this._mayGet = false; console.warn("sqlite3_step() rc=",rc,"SQL =", api.sqlite3_sql(this._pStmt)); this.db.checkRc(rc); }; }, /** Fetches the value from the given 0-based column index of the current data row, throwing if index is out of range. Requires that step() has just returned a truthy value, else an exception is thrown. By default it will determine the data type of the result automatically. If passed a second arugment, it must be one of the enumeration values for sqlite3 types, which are defined as members of the sqlite3 module: SQLITE_INTEGER, SQLITE_FLOAT, SQLITE_TEXT, SQLITE_BLOB. Any other value, except for undefined, will trigger an exception. Passing undefined is the same as not passing a value. It is legal to, e.g., fetch an integer value as a string, in which case sqlite3 will convert the value to a string. If ndx is an array, this function behaves a differently: it assigns the indexes of the array, from 0 to the number of result columns, to the values of the corresponding column, and returns that array. If ndx is a plain object, this function behaves even differentlier: it assigns the properties of the object to the values of their corresponding result columns. Blobs are returned as Uint8Array instances. Potential TODO: add type ID SQLITE_JSON, which fetches the result as a string and passes it (if it's not null) to JSON.parse(), returning the result of that. Until then, getJSON() can be used for that. */ get: function(ndx,asType){ if(!affirmStmtOpen(this)._mayGet){ toss("Stmt.step() has not (recently) returned true."); } if(Array.isArray(ndx)){ let i = 0; while(i32bits */ } case api.SQLITE_FLOAT: return api.sqlite3_column_double(this._pStmt, ndx); case api.SQLITE_TEXT: return api.sqlite3_column_text(this._pStmt, ndx); case api.SQLITE_BLOB: { const n = api.sqlite3_column_bytes(this._pStmt, ndx); const ptr = api.sqlite3_column_blob(this._pStmt, ndx); const rc = new Uint8Array(n); for(let i = 0; i < n; ++i) rc[i] = HEAP8[ptr + i]; return rc; } default: toss("Don't know how to translate", "type of result column #"+ndx+"."); } abort("Not reached."); }, /** Equivalent to get(ndx) but coerces the result to an integer. */ getInt: function(ndx){return this.get(ndx,api.SQLITE_INTEGER)}, /** Equivalent to get(ndx) but coerces the result to a float. */ getFloat: function(ndx){return this.get(ndx,api.SQLITE_FLOAT)}, /** Equivalent to get(ndx) but coerces the result to a string. */ getString: function(ndx){return this.get(ndx,api.SQLITE_TEXT)}, /** Equivalent to get(ndx) but coerces the result to a Uint8Array. */ getBlob: function(ndx){return this.get(ndx,api.SQLITE_BLOB)}, /** A convenience wrapper around get() which fetches the value as a string and then, if it is not null, passes it to JSON.parse(), returning that result. Throws if parsing fails. If the result is null, null is returned. An empty string, on the other hand, will trigger an exception. */ getJSON: function(ndx){ const s = this.get(ndx, api.SQLITE_STRING); return null===s ? s : JSON.parse(s); }, /** Returns the result column name of the given index, or throws if index is out of bounds or this statement has been finalized. This can be used without having run step() first. */ getColumnName: function(ndx){ return api.sqlite3_column_name( affirmColIndex(affirmStmtOpen(this),ndx)._pStmt, ndx ); }, /** If this statement potentially has result columns, this function returns an array of all such names. If passed an array, it is used as the target and all names are appended to it. Returns the target array. Throws if this statement cannot have result columns. This object's columnCount member holds the number of columns. */ getColumnNames: function(tgt){ affirmColIndex(affirmStmtOpen(this),0); if(!tgt) tgt = []; for(let i = 0; i < this.columnCount; ++i){ tgt.push(api.sqlite3_column_name(this._pStmt, i)); } return tgt; }, /** If this statement has named bindable parameters and the given name matches one, its 1-based bind index is returned. If no match is found, 0 is returned. If it has no bindable parameters, the undefined value is returned. */ getParamIndex: function(name){ return (affirmStmtOpen(this).parameterCount ? api.sqlite3_bind_parameter_index(this._pStmt, name) : undefined); } }/*Stmt.prototype*/; /** OO binding's namespace. */ const SQLite3 = { version: { lib: api.sqlite3_libversion(), ooApi: "0.0.1" }, DB, Stmt, /** Reports whether a given compile-time option, named by the given argument. It has several distinct uses: If optName is an array then it is expected to be a list of compilation options and this function returns an object which maps each such option to true or false, indicating whether or not the given option was included in this build. That object is returned. If optName is an object, its keys are expected to be compilation options and this function sets each entry to true or false. That object is returned. If passed no arguments then it returns an object mapping all known compilation options to their compile-time values, or boolean true if they are defined with no value. In all other cases it returns true if the given option was active when when compiling the sqlite3 module, else false. Compile-time option names may optionally include their "SQLITE_" prefix. When it returns an object of all options, the prefix is elided. */ compileOptionUsed: function f(optName){ if(!arguments.length){ if(!f._opt){ f._rx = /^([^=]+)=(.+)/; f._rxInt = /^-?\d+$/; f._opt = function(opt, rv){ const m = f._rx.exec(opt); rv[0] = (m ? m[1] : opt); rv[1] = m ? (f._rxInt.test(m[2]) ? +m[2] : m[2]) : true; }; } const rc = {}, ov = [0,0]; let i = 0, k; while((k = api.sqlite3_compileoption_get(i++))){ f._opt(k,ov); rc[ov[0]] = ov[1]; } return rc; } else if(Array.isArray(optName)){ const rc = {}; optName.forEach((v)=>{ rc[v] = api.sqlite3_compileoption_used(v); }); return rc; } else if('object' === typeof optName){ Object.keys(optName).forEach((k)=> { optName[k] = api.sqlite3_compileoption_used(k); }); return optName; } return ( 'string'===typeof optName ) ? !!api.sqlite3_compileoption_used(optName) : false; } }; namespace.sqlite3 = { api: api, SQLite3 }; });