Google Git
Sign in
chromium / chromium / deps / sqlite / refs/heads/upstream/js-cpp / . / ext / wasm / api / sqlite3-api-prologue.js
blob: fed1c56669631f1a92c7bccdce7e0a9684e23454 [file] [log] [blame] [edit]
/*
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 combined at build-time with other
related code, most notably a header and footer which wraps this whole
file into an Emscripten Module.postRun() handler which has a parameter
named "Module" (the Emscripten Module object). The exact requirements,
conventions, and build process are very much under construction and
will be (re)documented once they've stopped fluctuating so much.
Project home page: https://sqlite.org
Documentation home page: https://sqlite.org/wasm
Specific goals of this subproject:
- Except where noted in the non-goals, provide a more-or-less
feature-complete wrapper to the sqlite3 C API, insofar as WASM
feature parity with C allows for. In fact, provide at least 4
APIs...
1) 1-to-1 bindings as exported from WASM, with no automatic
type conversions between JS and C.
2) A binding of (1) which provides certain JS/C type conversions
to greatly simplify its use.
3) A higher-level API, more akin to sql.js and node.js-style
implementations. This one speaks directly to the low-level
API. This API must be used from the same thread as the
low-level API.
4) A second higher-level API which speaks to the previous APIs via
worker messages. This one is intended for use in the main
thread, with the lower-level APIs installed in a Worker thread,
and talking to them via Worker messages. Because Workers are
asynchronouns and have only a single message channel, some
acrobatics are needed here to feed async work results back to
the client (as we cannot simply pass around callbacks between
the main and Worker threads).
- Insofar as possible, support client-side storage using JS
filesystem APIs. As of this writing, such things are still very
much under development.
Specific non-goals of this project:
- As WASM is a web-centric technology and UTF-8 is the King of
Encodings in that realm, there are no currently plans to support
the UTF16-related sqlite3 APIs. They would add a complication to
the bindings for no appreciable benefit. Though web-related
implementation details take priority, and the JavaScript
components of the API specifically focus on browser clients, the
lower-level WASM module "should" work in non-web WASM
environments.
- Supporting old or niche-market platforms. WASM is built for a
modern web and requires modern platforms.
- Though scalar User-Defined Functions (UDFs) may be created in
JavaScript, there are currently no plans to add support for
aggregate and window functions.
Attribution:
This project is endebted to the work of sql.js:
https://github.com/sql-js/sql.js
sql.js was an essential stepping stone in this code's development as
it demonstrated how to handle some of the WASM-related voodoo (like
handling pointers-to-pointers and adding JS implementations of
C-bound callback functions). These APIs have a considerably
different shape than sql.js's, however.
*/
/**
sqlite3ApiBootstrap() is the only global symbol persistently
exposed by this API. It is intended to be called one time at the
end of the API amalgamation process, passed configuration details
for the current environment, and then optionally be removed from
the global object using `delete self.sqlite3ApiBootstrap`.
This function expects a configuration object, intended to abstract
away details specific to any given WASM environment, primarily so
that it can be used without any _direct_ dependency on
Emscripten. (Note the default values for the config object!) The
config object is only honored the first time this is
called. Subsequent calls ignore the argument and return the same
(configured) object which gets initialized by the first call.
This function will throw if any of the required config options are
missing.
The config object properties include:
- `exports`[^1]: the "exports" object for the current WASM
environment. In an Emscripten-based build, this should be set to
`Module['asm']`.
- `memory`[^1]: optional WebAssembly.Memory object, defaulting to
`exports.memory`. In Emscripten environments this should be set
to `Module.wasmMemory` if the build uses `-sIMPORT_MEMORY`, or be
left undefined/falsy to default to `exports.memory` when using
WASM-exported memory.
- `bigIntEnabled`: true if BigInt support is enabled. Defaults to
true if `self.BigInt64Array` is available, else false. Some APIs
will throw exceptions if called without BigInt support, as BigInt
is required for marshalling C-side int64 into and out of JS.
- `allocExportName`: the name of the function, in `exports`, of the
`malloc(3)`-compatible routine for the WASM environment. Defaults
to `"malloc"`.
- `deallocExportName`: the name of the function, in `exports`, of
the `free(3)`-compatible routine for the WASM
environment. Defaults to `"free"`.
- `wasmfsOpfsDir`[^1]: if the environment supports persistent
storage, this directory names the "mount point" for that
directory. It must be prefixed by `/` and may contain only a
single directory-name part. Using the root directory name is not
supported by any current persistent backend. This setting is
only used in WASMFS-enabled builds.
[^1] = This property may optionally be a function, in which case this
function re-assigns it to the value returned from that function,
enabling delayed evaluation.
*/
'use strict';
self.sqlite3ApiBootstrap = function sqlite3ApiBootstrap(
apiConfig = (self.sqlite3ApiConfig || sqlite3ApiBootstrap.defaultConfig)
){
if(sqlite3ApiBootstrap.sqlite3){ /* already initalized */
console.warn("sqlite3ApiBootstrap() called multiple times.",
"Config and external initializers are ignored on calls after the first.");
return sqlite3ApiBootstrap.sqlite3;
}
const config = Object.assign(Object.create(null),{
exports: undefined,
memory: undefined,
bigIntEnabled: (()=>{
if('undefined'!==typeof Module){
/* Emscripten module will contain HEAPU64 when built with
-sWASM_BIGINT=1, else it will not. */
return !!Module.HEAPU64;
}
return !!self.BigInt64Array;
})(),
allocExportName: 'malloc',
deallocExportName: 'free',
wasmfsOpfsDir: '/opfs'
}, apiConfig || {});
[
// If any of these config options are functions, replace them with
// the result of calling that function...
'exports', 'memory', 'wasmfsOpfsDir'
].forEach((k)=>{
if('function' === typeof config[k]){
config[k] = config[k]();
}
});
/**
The main sqlite3 binding API gets installed into this object,
mimicking the C API as closely as we can. The numerous members
names with prefixes 'sqlite3_' and 'SQLITE_' behave, insofar as
possible, identically to the C-native counterparts, as documented at:
https://www.sqlite.org/c3ref/intro.html
A very few exceptions require an additional level of proxy
function or may otherwise require special attention in the WASM
environment, and all such cases are documented somewhere below
in this file or in sqlite3-api-glue.js. capi members which are
not documented are installed as 1-to-1 proxies for their
C-side counterparts.
*/
const capi = Object.create(null);
/**
Holds state which are specific to the WASM-related
infrastructure and glue code. It is not expected that client
code will normally need these, but they're exposed here in case
it does. These APIs are _not_ to be considered an
official/stable part of the sqlite3 WASM API. They may change
as the developers' experience suggests appropriate changes.
Note that a number of members of this object are injected
dynamically after the api object is fully constructed, so
not all are documented in this file.
*/
const wasm = Object.create(null);
/** Internal helper for SQLite3Error ctor. */
const __rcStr = (rc)=>{
return (capi.sqlite3_js_rc_str && capi.sqlite3_js_rc_str(rc))
|| ("Unknown result code #"+rc);
};
/** Internal helper for SQLite3Error ctor. */
const __isInt = (n)=>'number'===typeof n && n===(n | 0);
/**
An Error subclass specifically for reporting DB-level errors and
enabling clients to unambiguously identify such exceptions.
The C-level APIs never throw, but some of the higher-level
C-style APIs do and the object-oriented APIs use exceptions
exclusively to report errors.
*/
class SQLite3Error extends Error {
/**
Constructs this object with a message depending on its arguments:
- If it's passed only a single integer argument, it is assumed
to be an sqlite3 C API result code. The message becomes the
result of sqlite3.capi.sqlite3_js_rc_str() or (if that returns
falsy) a synthesized string which contains that integer.
- If passed 2 arguments and the 2nd is a object, it bevaves
like the Error(string,object) constructor except that the first
argument is subject to the is-integer semantics from the
previous point.
- Else all arguments are concatenated with a space between each
one, using args.join(' '), to create the error message.
*/
constructor(...args){
if(1===args.length && __isInt(args[0])){
super(__rcStr(args[0]));
}else if(2===args.length && 'object'===typeof args){
if(__isInt(args[0])) super(__rcStr(args[0]), args[1]);
else super(...args);
}else{
super(args.join(' '));
}
this.name = 'SQLite3Error';
}
};
/**
Functionally equivalent to the SQLite3Error constructor but may
be used as part of an expression, e.g.:
```
return someFunction(x) || SQLite3Error.toss(...);
```
*/
SQLite3Error.toss = (...args)=>{
throw new SQLite3Error(...args);
};
const toss3 = SQLite3Error.toss;
if(config.wasmfsOpfsDir && !/^\/[^/]+$/.test(config.wasmfsOpfsDir)){
toss3("config.wasmfsOpfsDir must be falsy or in the form '/dir-name'.");
}
/**
Returns true if n is a 32-bit (signed) integer, else
false. This is used for determining when we need to switch to
double-type DB operations for integer values in order to keep
more precision.
*/
const isInt32 = (n)=>{
return ('bigint'!==typeof n /*TypeError: can't convert BigInt to number*/)
&& !!(n===(n|0) && n<=2147483647 && n>=-2147483648);
};
/**
Returns true if the given BigInt value is small enough to fit
into an int64 value, else false.
*/
const bigIntFits64 = function f(b){
if(!f._max){
f._max = BigInt("0x7fffffffffffffff");
f._min = ~f._max;
}
return b >= f._min && b <= f._max;
};
/**
Returns true if the given BigInt value is small enough to fit
into an int32, else false.
*/
const bigIntFits32 = (b)=>(b >= (-0x7fffffffn - 1n) && b <= 0x7fffffffn);
/**
Returns true if the given BigInt value is small enough to fit
into a double value without loss of precision, else false.
*/
const bigIntFitsDouble = function f(b){
if(!f._min){
f._min = Number.MIN_SAFE_INTEGER;
f._max = Number.MAX_SAFE_INTEGER;
}
return b >= f._min && b <= f._max;
};
/** Returns v if v appears to be a TypedArray, else false. */
const isTypedArray = (v)=>{
return (v && v.constructor && isInt32(v.constructor.BYTES_PER_ELEMENT)) ? v : false;
};
/** Internal helper to use in operations which need to distinguish
between TypedArrays which are backed by a SharedArrayBuffer
from those which are not. */
const __SAB = ('undefined'===typeof SharedArrayBuffer)
? function(){} : SharedArrayBuffer;
/** Returns true if the given TypedArray object is backed by a
SharedArrayBuffer, else false. */
const isSharedTypedArray = (aTypedArray)=>(aTypedArray.buffer instanceof __SAB);
/**
Returns either aTypedArray.slice(begin,end) (if
aTypedArray.buffer is a SharedArrayBuffer) or
aTypedArray.subarray(begin,end) (if it's not).
This distinction is important for APIs which don't like to
work on SABs, e.g. TextDecoder, and possibly for our
own APIs which work on memory ranges which "might" be
modified by other threads while they're working.
*/
const typedArrayPart = (aTypedArray, begin, end)=>{
return isSharedTypedArray(aTypedArray)
? aTypedArray.slice(begin, end)
: aTypedArray.subarray(begin, end);
};
/**
Returns true if v appears to be one of our bind()-able
TypedArray types: Uint8Array or Int8Array. Support for
TypedArrays with element sizes >1 is TODO.
*/
const isBindableTypedArray = (v)=>{
return v && v.constructor && (1===v.constructor.BYTES_PER_ELEMENT);
};
/**
Returns true if v appears to be one of the TypedArray types
which is legal for holding SQL code (as opposed to binary blobs).
Currently this is the same as isBindableTypedArray() but it
seems likely that we'll eventually want to add Uint32Array
and friends to the isBindableTypedArray() list but not to the
isSQLableTypedArray() list.
*/
const isSQLableTypedArray = (v)=>{
return v && v.constructor && (1===v.constructor.BYTES_PER_ELEMENT);
};
/** Returns true if isBindableTypedArray(v) does, else throws with a message
that v is not a supported TypedArray value. */
const affirmBindableTypedArray = (v)=>{
return isBindableTypedArray(v)
|| toss3("Value is not of a supported TypedArray type.");
};
const utf8Decoder = new TextDecoder('utf-8');
/**
Uses TextDecoder to decode the given half-open range of the
given TypedArray to a string. This differs from a simple
call to TextDecoder in that it accounts for whether the
first argument is backed by a SharedArrayBuffer or not,
and can work more efficiently if it's not (TextDecoder
refuses to act upon an SAB).
*/
const typedArrayToString = function(typedArray, begin, end){
return utf8Decoder.decode(typedArrayPart(typedArray, begin,end));
};
/**
If v is-a Array, its join("") result is returned. If
isSQLableTypedArray(v) is true then typedArrayToString(v) is
returned. If it looks like a WASM pointer, wasm.cstringToJs(v) is
returned. Else v is returned as-is.
*/
const flexibleString = function(v){
if(isSQLableTypedArray(v)) return typedArrayToString(v);
else if(Array.isArray(v)) return v.join("");
else if(wasm.isPtr(v)) v = wasm.cstringToJs(v);
return v;
};
/**
An Error subclass specifically for reporting Wasm-level malloc()
failure and enabling clients to unambiguously identify such
exceptions.
*/
class WasmAllocError extends Error {
/**
If called with 2 arguments and the 2nd one is an object, it
behaves like the Error constructor, else it concatenates all
arguments together with a single space between each to
construct an error message string. As a special case, if
called with no arguments then it uses a default error
message.
*/
constructor(...args){
if(2===args.length && 'object'===typeof args){
super(...args);
}else if(args.length){
super(args.join(' '));
}else{
super("Allocation failed.");
}
this.name = 'WasmAllocError';
}
};
/**
Functionally equivalent to the WasmAllocError constructor but may
be used as part of an expression, e.g.:
```
return someAllocatingFunction(x) || WasmAllocError.toss(...);
```
*/
WasmAllocError.toss = (...args)=>{
throw new WasmAllocError(...args);
};
Object.assign(capi, {
/**
sqlite3_create_function_v2() differs from its native
counterpart only in the following ways:
1) The fourth argument (`eTextRep`) argument must not specify
any encoding other than sqlite3.SQLITE_UTF8. The JS API does not
currently support any other encoding and likely never
will. This function does not replace that argument on its own
because it may contain other flags.
2) Any of the four final arguments may be either WASM pointers
(assumed to be function pointers) or JS Functions. In the
latter case, each gets bound to WASM using
sqlite3.capi.wasm.installFunction() and that wrapper is passed
on to the native implementation.
The semantics of JS functions are:
xFunc: is passed `(pCtx, ...values)`. Its return value becomes
the new SQL function's result.
xStep: is passed `(pCtx, ...values)`. Its return value is
ignored.
xFinal: is passed `(pCtx)`. Its return value becomes the new
aggregate SQL function's result.
xDestroy: is passed `(void*)`. Its return value is ignored. The
pointer passed to it is the one from the 5th argument to
sqlite3_create_function_v2().
Note that:
- `pCtx` in the above descriptions is a `sqlite3_context*`. At
least 99 times out of a hundred, that initial argument will
be irrelevant for JS UDF bindings, but it needs to be there
so that the cases where it _is_ relevant, in particular with
window and aggregate functions, have full access to the
lower-level sqlite3 APIs.
- When wrapping JS functions, the remaining arguments are passd
to them as positional arguments, not as an array of
arguments, because that allows callback definitions to be
more JS-idiomatic than C-like. For example `(pCtx,a,b)=>a+b`
is more intuitive and legible than
`(pCtx,args)=>args[0]+args[1]`. For cases where an array of
arguments would be more convenient, the callbacks simply need
to be declared like `(pCtx,...args)=>{...}`, in which case
`args` will be an array.
- If a JS wrapper throws, it gets translated to
sqlite3_result_error() or sqlite3_result_error_nomem(),
depending on whether the exception is an
sqlite3.WasmAllocError object or not.
- When passing on WASM function pointers, arguments are _not_
converted or reformulated. They are passed on as-is in raw
pointer form using their native C signatures. Only JS
functions passed in to this routine, and thus wrapped by this
routine, get automatic conversions of arguments and result
values. The routines which perform those conversions are
exposed for client-side use as
sqlite3_create_function_v2.convertUdfArgs() and
sqlite3_create_function_v2.setUdfResult(). sqlite3_create_function()
and sqlite3_create_window_function() have those same methods.
For xFunc(), xStep(), and xFinal():
- 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 may be treated as
doubles or BigInts.
If any JS-side bound functions throw, those exceptions are
intercepted and converted to database-side errors with the
exception of xDestroy(): any exception from it is ignored,
possibly generating a console.error() message. Destructors
must not throw.
Once installed, there is currently no way to uninstall the
automatically-converted WASM-bound JS functions from WASM. They
can be uninstalled from the database as documented in the C
API, but this wrapper currently has no infrastructure in place
to also free the WASM-bound JS wrappers, effectively resulting
in a memory leak if the client uninstalls the UDF. Improving that
is a potential TODO, but removing client-installed UDFs is rare
in practice. If this factor is relevant for a given client,
they can create WASM-bound JS functions themselves, hold on to their
pointers, and pass the pointers in to here. Later on, they can
free those pointers (using `wasm.uninstallFunction()` or
equivalent).
C reference: https://www.sqlite.org/c3ref/create_function.html
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.
*/
sqlite3_create_function_v2: function(
pDb, funcName, nArg, eTextRep, pApp,
xFunc, xStep, xFinal, xDestroy
){/*installed later*/},
/**
Equivalent to passing the same arguments to
sqlite3_create_function_v2(), with 0 as the final argument.
*/
sqlite3_create_function:function(
pDb, funcName, nArg, eTextRep, pApp,
xFunc, xStep, xFinal
){/*installed later*/},
/**
The sqlite3_create_window_function() JS wrapper differs from
its native implementation in the exact same way that
sqlite3_create_function_v2() does. The additional function,
xInverse(), is treated identically to xStep() by the wrapping
layer.
*/
sqlite3_create_window_function: function(
pDb, funcName, nArg, eTextRep, pApp,
xStep, xFinal, xValue, xInverse, xDestroy
){/*installed later*/},
/**
The sqlite3_prepare_v3() binding handles two different uses
with differing JS/WASM semantics:
1) sqlite3_prepare_v3(pDb, sqlString, -1, prepFlags, ppStmt , null)
2) sqlite3_prepare_v3(pDb, sqlPointer, sqlByteLen, prepFlags, ppStmt, sqlPointerToPointer)
Note that the SQL length argument (the 3rd argument) must, for
usage (1), always be negative because it must be a byte length
and that value is expensive to calculate from JS (where only
the character length of strings is readily available). It is
retained in this API's interface for code/documentation
compatibility reasons but is currently _always_ ignored. With
usage (2), the 3rd argument is used as-is but is is still
critical that the C-style input string (2nd argument) be
terminated with a 0 byte.
In usage (1), the 2nd argument must be of type string,
Uint8Array, or Int8Array (either of which is assumed to
hold SQL). If it is, this function assumes case (1) and
calls the underyling C function with the equivalent of:
(pDb, sqlAsString, -1, prepFlags, ppStmt, null)
The `pzTail` argument is ignored in this case because its
result is meaningless when a string-type value is passed
through: the string goes through another level of internal
conversion for WASM's sake and the result pointer would refer
to that transient conversion's memory, not the passed-in
string.
If the sql argument is not a string, it must be a _pointer_ to
a NUL-terminated string which was allocated in the WASM memory
(e.g. using capi.wasm.alloc() or equivalent). In that case,
the final argument may be 0/null/undefined or must be a pointer
to which the "tail" of the compiled SQL is written, as
documented for the C-side sqlite3_prepare_v3(). In case (2),
the underlying C function is called with the equivalent of:
(pDb, sqlAsPointer, sqlByteLen, prepFlags, ppStmt, pzTail)
It returns its result and compiled statement as documented in
the C API. Fetching the output pointers (5th and 6th
parameters) requires using `capi.wasm.getMemValue()` (or
equivalent) and the `pzTail` will point to an address relative to
the `sqlAsPointer` value.
If passed an invalid 2nd argument type, this function will
return SQLITE_MISUSE and sqlite3_errmsg() will contain a string
describing the problem.
Side-note: if given an empty string, or one which contains only
comments or an empty SQL expression, 0 is returned but the result
output pointer will be NULL.
*/
sqlite3_prepare_v3: (dbPtr, sql, sqlByteLen, prepFlags,
stmtPtrPtr, strPtrPtr)=>{}/*installed later*/,
/**
Equivalent to calling sqlite3_prapare_v3() with 0 as its 4th argument.
*/
sqlite3_prepare_v2: (dbPtr, sql, sqlByteLen,
stmtPtrPtr,strPtrPtr)=>{}/*installed later*/,
/**
This binding enables the callback argument to be a JavaScript.
If the callback is a function, then for the duration of the
sqlite3_exec() call, it installs a WASM-bound function which
acts as a proxy for the given callback. That proxy will also
perform a conversion of the callback's arguments from
`(char**)` to JS arrays of strings. However, for API
consistency's sake it will still honor the C-level callback
parameter order and will call it like:
`callback(pVoid, colCount, listOfValues, listOfColNames)`
If the callback is not a JS function then this binding performs
no translation of the callback, but the sql argument is still
converted to a WASM string for the call using the
"flexible-string" argument converter.
*/
sqlite3_exec: (pDb, sql, callback, pVoid, pErrMsg)=>{}/*installed later*/,
/**
If passed a single argument which appears to be a byte-oriented
TypedArray (Int8Array or Uint8Array), this function treats that
TypedArray as an output target, fetches `theArray.byteLength`
bytes of randomness, and populates the whole array with it. As
a special case, if the array's length is 0, this function
behaves as if it were passed (0,0). When called this way, it
returns its argument, else it returns the `undefined` value.
If called with any other arguments, they are passed on as-is
to the C API. Results are undefined if passed any incompatible
values.
*/
sqlite3_randomness: (n, outPtr)=>{/*installed later*/},
}/*capi*/);
/**
Various internal-use utilities are added here as needed. They
are bound to an object only so that we have access to them in
the differently-scoped steps of the API bootstrapping
process. At the end of the API setup process, this object gets
removed. These are NOT part of the public API.
*/
const util = {
affirmBindableTypedArray, flexibleString,
bigIntFits32, bigIntFits64, bigIntFitsDouble,
isBindableTypedArray,
isInt32, isSQLableTypedArray, isTypedArray,
typedArrayToString,
isUIThread: ()=>'undefined'===typeof WorkerGlobalScope,
isSharedTypedArray,
typedArrayPart
};
Object.assign(wasm, {
/**
Emscripten APIs have a deep-seated assumption that all pointers
are 32 bits. We'll remain optimistic that that won't always be
the case and will use this constant in places where we might
otherwise use a hard-coded 4.
*/
ptrSizeof: config.wasmPtrSizeof || 4,
/**
The WASM IR (Intermediate Representation) value for
pointer-type values. It MUST refer to a value type of the
size described by this.ptrSizeof _or_ it may be any value
which ends in '*', which Emscripten's glue code internally
translates to i32.
*/
ptrIR: config.wasmPtrIR || "i32",
/**
True if BigInt support was enabled via (e.g.) the
Emscripten -sWASM_BIGINT flag, else false. When
enabled, certain 64-bit sqlite3 APIs are enabled which
are not otherwise enabled due to JS/WASM int64
impedence mismatches.
*/
bigIntEnabled: !!config.bigIntEnabled,
/**
The symbols exported by the WASM environment.
*/
exports: config.exports
|| toss3("Missing API config.exports (WASM module exports)."),
/**
When Emscripten compiles with `-sIMPORT_MEMORY`, it
initalizes the heap and imports it into wasm, as opposed to
the other way around. In this case, the memory is not
available via this.exports.memory.
*/
memory: config.memory || config.exports['memory']
|| toss3("API config object requires a WebAssembly.Memory object",
"in either config.exports.memory (exported)",
"or config.memory (imported)."),
/**
The API's one single point of access to the WASM-side memory
allocator. Works like malloc(3) (and is likely bound to
malloc()) but throws an WasmAllocError if allocation fails. It is
important that any code which might pass through the sqlite3 C
API NOT throw and must instead return SQLITE_NOMEM (or
equivalent, depending on the context).
Very few cases in the sqlite3 JS APIs can result in
client-defined functions propagating exceptions via the C-style
API. Most notably, this applies to WASM-bound JS functions
which are created directly by clients and passed on _as WASM
function pointers_ to functions such as
sqlite3_create_function_v2(). Such bindings created
transparently by this API will automatically use wrappers which
catch exceptions and convert them to appropriate error codes.
For cases where non-throwing allocation is required, use
sqlite3.wasm.alloc.impl(), which is direct binding of the
underlying C-level allocator.
Design note: this function is not named "malloc" primarily
because Emscripten uses that name and we wanted to avoid any
confusion early on in this code's development, when it still
had close ties to Emscripten's glue code.
*/
alloc: undefined/*installed later*/,
/**
The API's one single point of access to the WASM-side memory
deallocator. Works like free(3) (and is likely bound to
free()).
Design note: this function is not named "free" for the same
reason that this.alloc() is not called this.malloc().
*/
dealloc: undefined/*installed later*/
/* Many more wasm-related APIs get installed later on. */
}/*wasm*/);
/**
wasm.alloc()'s srcTypedArray.byteLength bytes,
populates them with the values from the source
TypedArray, and returns the pointer to that memory. The
returned pointer must eventually be passed to
wasm.dealloc() to clean it up.
As a special case, to avoid further special cases where
this is used, if srcTypedArray.byteLength is 0, it
allocates a single byte and sets it to the value
0. Even in such cases, calls must behave as if the
allocated memory has exactly srcTypedArray.byteLength
bytes.
ACHTUNG: this currently only works for Uint8Array and
Int8Array types and will throw if srcTypedArray is of
any other type.
*/
wasm.allocFromTypedArray = function(srcTypedArray){
affirmBindableTypedArray(srcTypedArray);
const pRet = wasm.alloc(srcTypedArray.byteLength || 1);
wasm.heapForSize(srcTypedArray.constructor).set(
srcTypedArray.byteLength ? srcTypedArray : [0], pRet
);
return pRet;
};
const keyAlloc = config.allocExportName || 'malloc',
keyDealloc = config.deallocExportName || 'free';
for(const key of [keyAlloc, keyDealloc]){
const f = wasm.exports[key];
if(!(f instanceof Function)) toss3("Missing required exports[",key,"] function.");
}
wasm.alloc = function f(n){
const m = f.impl(n);
if(!m) throw new WasmAllocError("Failed to allocate",n," bytes.");
return m;
};
wasm.alloc.impl = wasm.exports[keyAlloc];
wasm.dealloc = wasm.exports[keyDealloc];
/**
Reports info about compile-time options using
sqlite_compileoption_get() and sqlite3_compileoption_used(). 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,
indicating whether the compilation option was used or not. 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. This
result, which is relatively expensive to compute, is cached
and returned for future no-argument calls.
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.
*/
wasm.compileOptionUsed = function f(optName){
if(!arguments.length){
if(f._result) return f._result;
else 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 = capi.sqlite3_compileoption_get(i++))){
f._opt(k,ov);
rc[ov[0]] = ov[1];
}
return f._result = rc;
}else if(Array.isArray(optName)){
const rc = {};
optName.forEach((v)=>{
rc[v] = capi.sqlite3_compileoption_used(v);
});
return rc;
}else if('object' === typeof optName){
Object.keys(optName).forEach((k)=> {
optName[k] = capi.sqlite3_compileoption_used(k);
});
return optName;
}
return (
'string'===typeof optName
) ? !!capi.sqlite3_compileoption_used(optName) : false;
}/*compileOptionUsed()*/;
/**
Signatures for the WASM-exported C-side functions. Each entry
is an array with 2+ elements:
[ "c-side name",
"result type" (wasm.xWrap() syntax),
[arg types in xWrap() syntax]
// ^^^ this needn't strictly be an array: it can be subsequent
// elements instead: [x,y,z] is equivalent to x,y,z
]
Note that support for the API-specific data types in the
result/argument type strings gets plugged in at a later phase in
the API initialization process.
*/
wasm.bindingSignatures = [
// Please keep these sorted by function name!
["sqlite3_aggregate_context","void*", "sqlite3_context*", "int"],
["sqlite3_bind_blob","int", "sqlite3_stmt*", "int", "*", "int", "*"
/* TODO: we should arguably write a custom wrapper which knows
how to handle Blob, TypedArrays, and JS strings. */
],
["sqlite3_bind_double","int", "sqlite3_stmt*", "int", "f64"],
["sqlite3_bind_int","int", "sqlite3_stmt*", "int", "int"],
["sqlite3_bind_null",undefined, "sqlite3_stmt*", "int"],
["sqlite3_bind_parameter_count", "int", "sqlite3_stmt*"],
["sqlite3_bind_parameter_index","int", "sqlite3_stmt*", "string"],
["sqlite3_bind_text","int", "sqlite3_stmt*", "int", "string", "int", "int"
/* We should arguably create a hand-written binding of
bind_text() which does more flexible text conversion, along
the lines of sqlite3_prepare_v3(). The slightly problematic
part is the final argument (text destructor). */
],
["sqlite3_close_v2", "int", "sqlite3*"],
["sqlite3_changes", "int", "sqlite3*"],
["sqlite3_clear_bindings","int", "sqlite3_stmt*"],
["sqlite3_column_blob","*", "sqlite3_stmt*", "int"],
["sqlite3_column_bytes","int", "sqlite3_stmt*", "int"],
["sqlite3_column_count", "int", "sqlite3_stmt*"],
["sqlite3_column_double","f64", "sqlite3_stmt*", "int"],
["sqlite3_column_int","int", "sqlite3_stmt*", "int"],
["sqlite3_column_name","string", "sqlite3_stmt*", "int"],
["sqlite3_column_text","string", "sqlite3_stmt*", "int"],
["sqlite3_column_type","int", "sqlite3_stmt*", "int"],
["sqlite3_compileoption_get", "string", "int"],
["sqlite3_compileoption_used", "int", "string"],
/* sqlite3_create_function(), sqlite3_create_function_v2(), and
sqlite3_create_window_function() use hand-written bindings to
simplify handling of their function-type arguments. */
["sqlite3_data_count", "int", "sqlite3_stmt*"],
["sqlite3_db_filename", "string", "sqlite3*", "string"],
["sqlite3_db_handle", "sqlite3*", "sqlite3_stmt*"],
["sqlite3_db_name", "string", "sqlite3*", "int"],
["sqlite3_deserialize", "int", "sqlite3*", "string", "*", "i64", "i64", "int"]
/* Careful! Short version: de/serialize() are problematic because they
might use a different allocator than the user for managing the
deserialized block. de/serialize() are ONLY safe to use with
sqlite3_malloc(), sqlite3_free(), and its 64-bit variants. */,
["sqlite3_errmsg", "string", "sqlite3*"],
["sqlite3_error_offset", "int", "sqlite3*"],
["sqlite3_errstr", "string", "int"],
/*["sqlite3_exec", "int", "sqlite3*", "string", "*", "*", "**"
Handled seperately to perform translation of the callback
into a WASM-usable one. ],*/
["sqlite3_expanded_sql", "string", "sqlite3_stmt*"],
["sqlite3_extended_errcode", "int", "sqlite3*"],
["sqlite3_extended_result_codes", "int", "sqlite3*", "int"],
["sqlite3_file_control", "int", "sqlite3*", "string", "int", "*"],
["sqlite3_finalize", "int", "sqlite3_stmt*"],
["sqlite3_free", undefined,"*"],
["sqlite3_initialize", undefined],
/*["sqlite3_interrupt", undefined, "sqlite3*"
^^^ we cannot actually currently support this because JS is
single-threaded and we don't have a portable way to access a DB
from 2 SharedWorkers concurrently. ],*/
["sqlite3_libversion", "string"],
["sqlite3_libversion_number", "int"],
["sqlite3_malloc", "*","int"],
["sqlite3_open", "int", "string", "*"],
["sqlite3_open_v2", "int", "string", "*", "int", "string"],
/* sqlite3_prepare_v2() and sqlite3_prepare_v3() are handled
separately due to us requiring two different sets of semantics
for those, depending on how their SQL argument is provided. */
/* sqlite3_randomness() uses a hand-written wrapper to extend
the range of supported argument types. */
["sqlite3_realloc", "*","*","int"],
["sqlite3_reset", "int", "sqlite3_stmt*"],
["sqlite3_result_blob",undefined, "*", "*", "int", "*"],
["sqlite3_result_double",undefined, "*", "f64"],
["sqlite3_result_error",undefined, "*", "string", "int"],
["sqlite3_result_error_code", undefined, "*", "int"],
["sqlite3_result_error_nomem", undefined, "*"],
["sqlite3_result_error_toobig", undefined, "*"],
["sqlite3_result_int",undefined, "*", "int"],
["sqlite3_result_null",undefined, "*"],
["sqlite3_result_text",undefined, "*", "string", "int", "*"],
["sqlite3_serialize","*", "sqlite3*", "string", "*", "int"],
["sqlite3_shutdown", undefined],
["sqlite3_sourceid", "string"],
["sqlite3_sql", "string", "sqlite3_stmt*"],
["sqlite3_step", "int", "sqlite3_stmt*"],
["sqlite3_strglob", "int", "string","string"],
["sqlite3_strlike", "int", "string","string","int"],
["sqlite3_trace_v2", "int", "sqlite3*", "int", "*", "*"],
["sqlite3_total_changes", "int", "sqlite3*"],
["sqlite3_uri_boolean", "int", "string", "string", "int"],
["sqlite3_uri_key", "string", "string", "int"],
["sqlite3_uri_parameter", "string", "string", "string"],
["sqlite3_user_data","void*", "sqlite3_context*"],
["sqlite3_value_blob", "*", "sqlite3_value*"],
["sqlite3_value_bytes","int", "sqlite3_value*"],
["sqlite3_value_double","f64", "sqlite3_value*"],
["sqlite3_value_int","int", "sqlite3_value*"],
["sqlite3_value_text", "string", "sqlite3_value*"],
["sqlite3_value_type", "int", "sqlite3_value*"],
["sqlite3_vfs_find", "*", "string"],
["sqlite3_vfs_register", "int", "sqlite3_vfs*", "int"],
["sqlite3_vfs_unregister", "int", "sqlite3_vfs*"]
]/*wasm.bindingSignatures*/;
if(false && wasm.compileOptionUsed('SQLITE_ENABLE_NORMALIZE')){
/* ^^^ "the problem" is that this is an option feature and the
build-time function-export list does not currently take
optional features into account. */
wasm.bindingSignatures.push(["sqlite3_normalized_sql", "string", "sqlite3_stmt*"]);
}
/**
Functions which require BigInt (int64) support are separated from
the others because we need to conditionally bind them or apply
dummy impls, depending on the capabilities of the environment.
*/
wasm.bindingSignatures.int64 = [
["sqlite3_bind_int64","int", ["sqlite3_stmt*", "int", "i64"]],
["sqlite3_changes64","i64", ["sqlite3*"]],
["sqlite3_column_int64","i64", ["sqlite3_stmt*", "int"]],
["sqlite3_malloc64", "*","i64"],
["sqlite3_msize", "i64", "*"],
["sqlite3_realloc64", "*","*", "i64"],
["sqlite3_result_int64",undefined, "*", "i64"],
["sqlite3_total_changes64", "i64", ["sqlite3*"]],
["sqlite3_uri_int64", "i64", ["string", "string", "i64"]],
["sqlite3_value_int64","i64", "sqlite3_value*"],
];
/**
Functions which are intended solely for API-internal use by the
WASM components, not client code. These get installed into
sqlite3.wasm.
*/
wasm.bindingSignatures.wasm = [
["sqlite3_wasm_db_reset", "int", "sqlite3*"],
["sqlite3_wasm_db_vfs", "sqlite3_vfs*", "sqlite3*","string"],
["sqlite3_wasm_vfs_create_file", "int",
"sqlite3_vfs*","string","*", "int"],
["sqlite3_wasm_vfs_unlink", "int", "sqlite3_vfs*","string"]
];
/**
sqlite3.wasm.pstack (pseudo-stack) holds a special-case
stack-style allocator intended only for use with _small_ data of
not more than (in total) a few kb in size, managed as if it were
stack-based.
It has only a single intended usage:
```
const stackPos = pstack.pointer;
try{
const ptr = pstack.alloc(8);
// ==> pstack.pointer === ptr
const otherPtr = pstack.alloc(8);
// ==> pstack.pointer === otherPtr
...
}finally{
pstack.restore(stackPos);
// ==> pstack.pointer === stackPos
}
```
This allocator is much faster than a general-purpose one but is
limited to usage patterns like the one shown above.
It operates from a static range of memory which lives outside of
space managed by Emscripten's stack-management, so does not
collide with Emscripten-provided stack allocation APIs. The
memory lives in the WASM heap and can be used with routines such
as wasm.setMemValue() and any wasm.heap8u().slice().
*/
wasm.pstack = Object.assign(Object.create(null),{
/**
Sets the current pstack position to the given pointer. Results
are undefined if the passed-in value did not come from
this.pointer.
*/
restore: wasm.exports.sqlite3_wasm_pstack_restore,
/**
Attempts to allocate the given number of bytes from the
pstack. On success, it zeroes out a block of memory of the
given size, adjusts the pstack pointer, and returns a pointer
to the memory. On error, returns throws a WasmAllocError. The
memory must eventually be released using restore().
This method always adjusts the given value to be a multiple
of 8 bytes because failing to do so can lead to incorrect
results when reading and writing 64-bit values from/to the WASM
heap. Similarly, the returned address is always 8-byte aligned.
*/
alloc: (n)=>{
return wasm.exports.sqlite3_wasm_pstack_alloc(n)
|| WasmAllocError.toss("Could not allocate",n,
"bytes from the pstack.");
},
/**
alloc()'s n chunks, each sz bytes, as a single memory block and
returns the addresses as an array of n element, each holding
the address of one chunk.
Throws a WasmAllocError if allocation fails.
Example:
```
const [p1, p2, p3] = wasm.pstack.allocChunks(3,4);
```
*/
allocChunks: (n,sz)=>{
const mem = wasm.pstack.alloc(n * sz);
const rc = [];
let i = 0, offset = 0;
for(; i < n; offset = (sz * ++i)){
rc.push(mem + offset);
}
return rc;
},
/**
A convenience wrapper for allocChunks() which sizes each chunk
as either 8 bytes (safePtrSize is truthy) or wasm.ptrSizeof (if
safePtrSize is falsy).
How it returns its result differs depending on its first
argument: if it's 1, it returns a single pointer value. If it's
more than 1, it returns the same as allocChunks().
When a returned pointers will refer to a 64-bit value, e.g. a
double or int64, and that value must be written or fetched,
e.g. using wasm.setMemValue() or wasm.getMemValue(), it is
important that the pointer in question be aligned to an 8-byte
boundary or else it will not be fetched or written properly and
will corrupt or read neighboring memory.
However, when all pointers involved point to "small" data, it
is safe to pass a falsy value to save a tiny bit of memory.
*/
allocPtr: (n=1,safePtrSize=true)=>{
return 1===n
? wasm.pstack.alloc(safePtrSize ? 8 : wasm.ptrSizeof)
: wasm.pstack.allocChunks(n, safePtrSize ? 8 : wasm.ptrSizeof);
}
})/*wasm.pstack*/;
Object.defineProperties(wasm.pstack, {
/**
sqlite3.wasm.pstack.pointer resolves to the current pstack
position pointer. This value is intended _only_ to be saved
for passing to restore(). Writing to this memory, without
first reserving it via wasm.pstack.alloc() and friends, leads
to undefined results.
*/
pointer: {
configurable: false, iterable: true, writeable: false,
get: wasm.exports.sqlite3_wasm_pstack_ptr
//Whether or not a setter as an alternative to restore() is
//clearer or would just lead to confusion is unclear.
//set: wasm.exports.sqlite3_wasm_pstack_restore
},
/**
sqlite3.wasm.pstack.quota to the total number of bytes
available in the pstack, including any space which is currently
allocated. This value is a compile-time constant.
*/
quota: {
configurable: false, iterable: true, writeable: false,
get: wasm.exports.sqlite3_wasm_pstack_quota
},
/**
sqlite3.wasm.pstack.remaining resolves to the amount of space
remaining in the pstack.
*/
remaining: {
configurable: false, iterable: true, writeable: false,
get: wasm.exports.sqlite3_wasm_pstack_remaining
}
})/*wasm.pstack properties*/;
capi.sqlite3_randomness = (...args)=>{
if(1===args.length && util.isTypedArray(args[0])
&& 1===args[0].BYTES_PER_ELEMENT){
const ta = args[0];
if(0===ta.byteLength){
wasm.exports.sqlite3_randomness(0,0);
return ta;
}
const stack = wasm.pstack.pointer;
try {
let n = ta.byteLength, offset = 0;
const r = wasm.exports.sqlite3_randomness;
const heap = wasm.heap8u();
const nAlloc = n < 512 ? n : 512;
const ptr = wasm.pstack.alloc(nAlloc);
do{
const j = (n>nAlloc ? nAlloc : n);
r(j, ptr);
ta.set(typedArrayPart(heap, ptr, ptr+j), offset);
n -= j;
offset += j;
} while(n > 0);
}catch(e){
console.error("Highly unexpected (and ignored!) "+
"exception in sqlite3_randomness():",e);
}finally{
wasm.pstack.restore(stack);
}
return ta;
}
wasm.exports.sqlite3_randomness(...args);
};
/** State for sqlite3_wasmfs_opfs_dir(). */
let __wasmfsOpfsDir = undefined;
/**
If the wasm environment has a WASMFS/OPFS-backed persistent
storage directory, its path is returned by this function. If it
does not then it returns "" (noting that "" is a falsy value).
The first time this is called, this function inspects the current
environment to determine whether persistence support is available
and, if it is, enables it (if needed).
This function currently only recognizes the WASMFS/OPFS storage
combination and its path refers to storage rooted in the
Emscripten-managed virtual filesystem.
*/
capi.sqlite3_wasmfs_opfs_dir = function(){
if(undefined !== __wasmfsOpfsDir) return __wasmfsOpfsDir;
// If we have no OPFS, there is no persistent dir
const pdir = config.wasmfsOpfsDir;
if(!pdir
|| !self.FileSystemHandle
|| !self.FileSystemDirectoryHandle
|| !self.FileSystemFileHandle){
return __wasmfsOpfsDir = "";
}
try{
if(pdir && 0===wasm.xCallWrapped(
'sqlite3_wasm_init_wasmfs', 'i32', ['string'], pdir
)){
return __wasmfsOpfsDir = pdir;
}else{
return __wasmfsOpfsDir = "";
}
}catch(e){
// sqlite3_wasm_init_wasmfs() is not available
return __wasmfsOpfsDir = "";
}
};
/**
Experimental and subject to change or removal.
Returns true if sqlite3.capi.sqlite3_wasmfs_opfs_dir() is a
non-empty string and the given name starts with (that string +
'/'), else returns false.
*/
capi.sqlite3_wasmfs_filename_is_persistent = function(name){
const p = capi.sqlite3_wasmfs_opfs_dir();
return (p && name) ? name.startsWith(p+'/') : false;
};
// This bit is highly arguable and is incompatible with the fiddle shell.
if(false && 0===wasm.exports.sqlite3_vfs_find(0)){
/* Assume that sqlite3_initialize() has not yet been called.
This will be the case in an SQLITE_OS_KV build. */
wasm.exports.sqlite3_initialize();
}
/**
Given an `sqlite3*`, an sqlite3_vfs name, and an optional db name
(defaulting to "main"), returns a truthy value (see below) if
that db uses that VFS, else returns false. If pDb is falsy then
the 3rd argument is ignored and this function returns a truthy
value if the default VFS name matches that of the 2nd
argument. Results are undefined if pDb is truthy but refers to an
invalid pointer. The 3rd argument specifies the database name of
the given database connection to check, defaulting to the main
db.
The 2nd and 3rd arguments may either be a JS string or a WASM
C-string. If the 2nd argument is a NULL WASM pointer, the default
VFS is assumed. If the 3rd is a NULL WASM pointer, "main" is
assumed.
The truthy value it returns is a pointer to the `sqlite3_vfs`
object.
To permit safe use of this function from APIs which may be called
via the C stack (like SQL UDFs), this function does not throw: if
bad arguments cause a conversion error when passing into
wasm-space, false is returned.
*/
capi.sqlite3_js_db_uses_vfs = function(pDb,vfsName,dbName=0){
try{
const pK = capi.sqlite3_vfs_find(vfsName);
if(!pK) return false;
else if(!pDb){
return pK===capi.sqlite3_vfs_find(0) ? pK : false;
}else{
return pK===capi.sqlite3_js_db_vfs(pDb,dbName) ? pK : false;
}
}catch(e){
/* Ignore - probably bad args to a wasm-bound function. */
return false;
}
};
/**
Returns an array of the names of all currently-registered sqlite3
VFSes.
*/
capi.sqlite3_js_vfs_list = function(){
const rc = [];
let pVfs = capi.sqlite3_vfs_find(0);
while(pVfs){
const oVfs = new capi.sqlite3_vfs(pVfs);
rc.push(wasm.cstringToJs(oVfs.$zName));
pVfs = oVfs.$pNext;
oVfs.dispose();
}
return rc;
};
/**
Serializes the given `sqlite3*` pointer to a Uint8Array, as per
sqlite3_serialize(). On success it returns a Uint8Array. On
error it throws with a description of the problem.
*/
capi.sqlite3_js_db_export = function(pDb){
if(!pDb) toss3('Invalid sqlite3* argument.');
if(!wasm.bigIntEnabled) toss3('BigInt64 support is not enabled.');
const stack = wasm.pstack.pointer;
let pOut;
try{
const pSize = wasm.pstack.alloc(8/*i64*/ + wasm.ptrSizeof);
const ppOut = pSize + 8;
/**
Maintenance reminder, since this cost a full hour of grief
and confusion: if the order of pSize/ppOut are reversed in
that memory block, fetching the value of pSize after the
export reads a garbage size because it's not on an 8-byte
memory boundary!
*/
let rc = wasm.exports.sqlite3_wasm_db_serialize(
pDb, ppOut, pSize, 0
);
if(rc){
toss3("Database serialization failed with code",
sqlite3.capi.sqlite3_js_rc_str(rc));
}
pOut = wasm.getPtrValue(ppOut);
const nOut = wasm.getMemValue(pSize, 'i64');
rc = nOut
? wasm.heap8u().slice(pOut, pOut + Number(nOut))
: new Uint8Array();
return rc;
}finally{
if(pOut) wasm.exports.sqlite3_free(pOut);
wasm.pstack.restore(stack);
}
};
/**
Given a `sqlite3*` and a database name (JS string or WASM
C-string pointer, which may be 0), returns a pointer to the
sqlite3_vfs responsible for it. If the given db name is null/0,
or not provided, then "main" is assumed.
*/
capi.sqlite3_js_db_vfs =
(dbPointer, dbName=0)=>wasm.sqlite3_wasm_db_vfs(dbPointer, dbName);
/**
A thin wrapper around capi.sqlite3_aggregate_context() which
behaves the same except that it throws a WasmAllocError if that
function returns 0. As a special case, if n is falsy it does
_not_ throw if that function returns 0. That special case is
intended for use with xFinal() implementations.
*/
capi.sqlite3_js_aggregate_context = (pCtx, n)=>{
return capi.sqlite3_aggregate_context(pCtx, n)
|| (n ? WasmAllocError.toss("Cannot allocate",n,
"bytes for sqlite3_aggregate_context()")
: 0);
};
if( util.isUIThread() ){
/* Features specific to the main window thread... */
/**
Internal helper for sqlite3_js_kvvfs_clear() and friends.
Its argument should be one of ('local','session',"").
*/
const __kvvfsInfo = function(which){
const rc = Object.create(null);
rc.prefix = 'kvvfs-'+which;
rc.stores = [];
if('session'===which || ""===which) rc.stores.push(self.sessionStorage);
if('local'===which || ""===which) rc.stores.push(self.localStorage);
return rc;
};
/**
Clears all storage used by the kvvfs DB backend, deleting any
DB(s) stored there. Its argument must be either 'session',
'local', or "". In the first two cases, only sessionStorage
resp. localStorage is cleared. If it's an empty string (the
default) then both are cleared. Only storage keys which match
the pattern used by kvvfs are cleared: any other client-side
data are retained.
This function is only available in the main window thread.
Returns the number of entries cleared.
*/
capi.sqlite3_js_kvvfs_clear = function(which=""){
let rc = 0;
const kvinfo = __kvvfsInfo(which);
kvinfo.stores.forEach((s)=>{
const toRm = [] /* keys to remove */;
let i;
for( i = 0; i < s.length; ++i ){
const k = s.key(i);
if(k.startsWith(kvinfo.prefix)) toRm.push(k);
}
toRm.forEach((kk)=>s.removeItem(kk));
rc += toRm.length;
});
return rc;
};
/**
This routine guesses the approximate amount of
window.localStorage and/or window.sessionStorage in use by the
kvvfs database backend. Its argument must be one of
('session', 'local', ""). In the first two cases, only
sessionStorage resp. localStorage is counted. If it's an empty
string (the default) then both are counted. Only storage keys
which match the pattern used by kvvfs are counted. The returned
value is the "length" value of every matching key and value,
noting that JavaScript stores each character in 2 bytes.
Note that the returned size is not authoritative from the
perspective of how much data can fit into localStorage and
sessionStorage, as the precise algorithms for determining
those limits are unspecified and may include per-entry
overhead invisible to clients.
*/
capi.sqlite3_js_kvvfs_size = function(which=""){
let sz = 0;
const kvinfo = __kvvfsInfo(which);
kvinfo.stores.forEach((s)=>{
let i;
for(i = 0; i < s.length; ++i){
const k = s.key(i);
if(k.startsWith(kvinfo.prefix)){
sz += k.length;
sz += s.getItem(k).length;
}
}
});
return sz * 2 /* because JS uses 2-byte char encoding */;
};
}/* main-window-only bits */
/* The remainder of the API will be set up in later steps. */
const sqlite3 = {
WasmAllocError: WasmAllocError,
SQLite3Error: SQLite3Error,
capi,
util,
wasm,
config,
/**
Holds the version info of the sqlite3 source tree from which
the generated sqlite3-api.js gets built. Note that its version
may well differ from that reported by sqlite3_libversion(), but
that should be considered a source file mismatch, as the JS and
WASM files are intended to be built and distributed together.
This object is initially a placeholder which gets replaced by a
build-generated object.
*/
version: Object.create(null),
/**
Performs any optional asynchronous library-level initialization
which might be required. This function returns a Promise which
resolves to the sqlite3 namespace object. Any error in the
async init will be fatal to the init as a whole, but init
routines are themselves welcome to install dummy catch()
handlers which are not fatal if their failure should be
considered non-fatal. If called more than once, the second and
subsequent calls are no-ops which return a pre-resolved
Promise.
Ideally this function is called as part of the Promise chain
which handles the loading and bootstrapping of the API. If not
then it must be called by client-level code, which must not use
the library until the returned promise resolves.
Bug: if called while a prior call is still resolving, the 2nd
call will resolve prematurely, before the 1st call has finished
resolving. The current build setup precludes that possibility,
so it's only a hypothetical problem if/when this function
ever needs to be invoked by clients.
In Emscripten-based builds, this function is called
automatically and deleted from this object.
*/
asyncPostInit: async function(){
let lip = sqlite3ApiBootstrap.initializersAsync;
delete sqlite3ApiBootstrap.initializersAsync;
if(!lip || !lip.length) return Promise.resolve(sqlite3);
// Is it okay to resolve these in parallel or do we need them
// to resolve in order? We currently only have 1, so it
// makes no difference.
lip = lip.map((f)=>{
const p = (f instanceof Promise) ? f : f(sqlite3);
return p.catch((e)=>{
console.error("an async sqlite3 initializer failed:",e);
throw e;
});
});
//let p = lip.shift();
//while(lip.length) p = p.then(lip.shift());
//return p.then(()=>sqlite3);
return Promise.all(lip).then(()=>sqlite3);
},
/**
scriptInfo ideally gets injected into this object by the
infrastructure which assembles the JS/WASM module. It contains
state which must be collected before sqlite3ApiBootstrap() can
be declared. It is not necessarily available to any
sqlite3ApiBootstrap.initializers but "should" be in place (if
it's added at all) by the time that
sqlite3ApiBootstrap.initializersAsync is processed.
This state is not part of the public API, only intended for use
with the sqlite3 API bootstrapping and wasm-loading process.
*/
scriptInfo: undefined
};
try{
sqlite3ApiBootstrap.initializers.forEach((f)=>{
f(sqlite3);
});
}catch(e){
/* If we don't report this here, it can get completely swallowed
up and disappear into the abyss of Promises and Workers. */
console.error("sqlite3 bootstrap initializer threw:",e);
throw e;
}
delete sqlite3ApiBootstrap.initializers;
sqlite3ApiBootstrap.sqlite3 = sqlite3;
return sqlite3;
}/*sqlite3ApiBootstrap()*/;
/**
self.sqlite3ApiBootstrap.initializers is an internal detail used by
the various pieces of the sqlite3 API's amalgamation process. It
must not be modified by client code except when plugging such code
into the amalgamation process.
Each component of the amalgamation is expected to append a function
to this array. When sqlite3ApiBootstrap() is called for the first
time, each such function will be called (in their appended order)
and passed the sqlite3 namespace object, into which they can install
their features (noting that most will also require that certain
features alread have been installed). At the end of that process,
this array is deleted.
Note that the order of insertion into this array is significant for
some pieces. e.g. sqlite3.capi and sqlite3.wasm cannot be fully
utilized until the whwasmutil.js part is plugged in via
sqlite3-api-glue.js.
*/
self.sqlite3ApiBootstrap.initializers = [];
/**
self.sqlite3ApiBootstrap.initializersAsync is an internal detail
used by the sqlite3 API's amalgamation process. It must not be
modified by client code except when plugging such code into the
amalgamation process.
The counterpart of self.sqlite3ApiBootstrap.initializers,
specifically for initializers which are asynchronous. All entries in
this list must be either async functions, non-async functions which
return a Promise, or a Promise. Each function in the list is called
with the sqlite3 ojbect as its only argument.
The resolved value of any Promise is ignored and rejection will kill
the asyncPostInit() process (at an indeterminate point because all
of them are run asynchronously in parallel).
This list is not processed until the client calls
sqlite3.asyncPostInit(). This means, for example, that intializers
added to self.sqlite3ApiBootstrap.initializers may push entries to
this list.
*/
self.sqlite3ApiBootstrap.initializersAsync = [];
/**
Client code may assign sqlite3ApiBootstrap.defaultConfig an
object-type value before calling sqlite3ApiBootstrap() (without
arguments) in order to tell that call to use this object as its
default config value. The intention of this is to provide
downstream clients with a reasonably flexible approach for plugging in
an environment-suitable configuration without having to define a new
global-scope symbol.
*/
self.sqlite3ApiBootstrap.defaultConfig = Object.create(null);
/**
Placeholder: gets installed by the first call to
self.sqlite3ApiBootstrap(). However, it is recommended that the
caller of sqlite3ApiBootstrap() capture its return value and delete
self.sqlite3ApiBootstrap after calling it. It returns the same
value which will be stored here.
*/
self.sqlite3ApiBootstrap.sqlite3 = undefined;