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Refactor: handle view encoding (Uint8Array) natively (#43)
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Replaces the internal asBuffer option with an encoding option that
can be one of buffer, utf8 or view, and converts data accordingly.
No longer have to transcode view to buffer.
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@vweevers
vweevers authored Jun 19, 2022
1 parent d6437b4 commit b9fd5e9
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Showing 3 changed files with 68 additions and 67 deletions.
130 changes: 65 additions & 65 deletions binding.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,7 @@ static void iterator_close_do (napi_env env, Iterator* iterator, napi_value cb);
#define NAPI_ARGV_UTF8_NEW(name, i) \
NAPI_UTF8_NEW(name, argv[i])

// TODO: consider using encoding options instead of type checking
#define LD_STRING_OR_BUFFER_TO_COPY(env, from, to) \
char* to##Ch_ = 0; \
size_t to##Sz_ = 0; \
Expand All @@ -61,6 +62,18 @@ static void iterator_close_do (napi_env env, Iterator* iterator, napi_value cb);
napi_get_buffer_info(env, from, (void **)&buf, &to##Sz_); \
to##Ch_ = new char[to##Sz_]; \
memcpy(to##Ch_, buf, to##Sz_); \
} else { \
char* buf = 0; \
napi_typedarray_type type; \
napi_status status = napi_get_typedarray_info(env, from, &type, &to##Sz_, (void **)&buf, NULL, NULL); \
if (status != napi_ok || type != napi_typedarray_type::napi_uint8_array) { \
/* TODO: refactor so that we can napi_throw_type_error() here */ \
to##Sz_ = 0; \
to##Ch_ = new char[to##Sz_]; \
} else { \
to##Ch_ = new char[to##Sz_]; \
memcpy(to##Ch_, buf, to##Sz_); \
} \
}

/*********************************************************************
Expand Down Expand Up @@ -149,20 +162,26 @@ static bool BooleanProperty (napi_env env, napi_value obj, const char* key,
return DEFAULT;
}

enum Encoding { buffer, utf8, view };

/**
* Returns true if the options object contains an encoding option that is "buffer"
* Returns internal Encoding enum matching the given encoding option.
*/
static bool EncodingIsBuffer (napi_env env, napi_value options, const char* option) {
static Encoding GetEncoding (napi_env env, napi_value options, const char* option) {
napi_value value;
size_t size;
size_t copied;
char buf[2];

if (napi_get_named_property(env, options, option, &value) == napi_ok &&
napi_get_value_string_utf8(env, value, NULL, 0, &size) == napi_ok) {
// Value is either "buffer" or "utf8" so we can tell them apart just by size
return size == 6;
napi_get_value_string_utf8(env, value, buf, 2, &copied) == napi_ok && copied == 1) {
// Value is either "buffer", "utf8" or "view" so we only have to read the first char
switch (buf[0]) {
case 'b': return Encoding::buffer;
case 'v': return Encoding::view;
}
}

return false;
return Encoding::utf8;
}

/**
Expand Down Expand Up @@ -234,35 +253,17 @@ static leveldb::Slice ToSlice (napi_env env, napi_value from) {
}

/**
* Returns length of string or buffer
*/
static size_t StringOrBufferLength (napi_env env, napi_value value) {
size_t size = 0;

if (IsString(env, value)) {
napi_get_value_string_utf8(env, value, NULL, 0, &size);
} else if (IsBuffer(env, value)) {
char* buf;
napi_get_buffer_info(env, value, (void **)&buf, &size);
}

return size;
}

/**
* Takes a Buffer or string property 'name' from 'opts'.
* Returns null if the property does not exist or is zero-length.
* Takes a Buffer, string or Uint8Array property 'name' from 'opts'.
* Returns null if the property does not exist.
*/
static std::string* RangeOption (napi_env env, napi_value opts, const char* name) {
if (HasProperty(env, opts, name)) {
napi_value value = GetProperty(env, opts, name);

if (StringOrBufferLength(env, value) >= 0) {
LD_STRING_OR_BUFFER_TO_COPY(env, value, to);
std::string* result = new std::string(toCh_, toSz_);
delete [] toCh_;
return result;
}
// TODO: we can avoid a copy here
LD_STRING_OR_BUFFER_TO_COPY(env, value, to);
std::string* result = new std::string(toCh_, toSz_);
delete [] toCh_;
return result;
}

return NULL;
Expand All @@ -281,8 +282,7 @@ static std::vector<std::string> KeyArray (napi_env env, napi_value arr) {
for (uint32_t i = 0; i < length; i++) {
napi_value element;

if (napi_get_element(env, arr, i, &element) == napi_ok &&
StringOrBufferLength(env, element) >= 0) {
if (napi_get_element(env, arr, i, &element) == napi_ok) {
LD_STRING_OR_BUFFER_TO_COPY(env, element, to);
result.emplace_back(toCh_, toSz_);
delete [] toCh_;
Expand Down Expand Up @@ -322,29 +322,29 @@ struct Entry {
: key_(key.data(), key.size()),
value_(value.data(), value.size()) {}

void ConvertByMode (napi_env env, Mode mode, const bool keyAsBuffer, const bool valueAsBuffer, napi_value& result) {
void ConvertByMode (napi_env env, Mode mode, const Encoding keyEncoding, const Encoding valueEncoding, napi_value& result) const {
if (mode == Mode::entries) {
napi_create_array_with_length(env, 2, &result);

napi_value keyElement;
napi_value valueElement;

Convert(env, &key_, keyAsBuffer, keyElement);
Convert(env, &value_, valueAsBuffer, valueElement);
Convert(env, &key_, keyEncoding, keyElement);
Convert(env, &value_, valueEncoding, valueElement);

napi_set_element(env, result, 0, keyElement);
napi_set_element(env, result, 1, valueElement);
} else if (mode == Mode::keys) {
Convert(env, &key_, keyAsBuffer, result);
Convert(env, &key_, keyEncoding, result);
} else {
Convert(env, &value_, valueAsBuffer, result);
Convert(env, &value_, valueEncoding, result);
}
}

static void Convert (napi_env env, const std::string* s, const bool asBuffer, napi_value& result) {
static void Convert (napi_env env, const std::string* s, const Encoding encoding, napi_value& result) {
if (s == NULL) {
napi_get_undefined(env, &result);
} else if (asBuffer) {
} else if (encoding == Encoding::buffer || encoding == Encoding::view) {
napi_create_buffer_copy(env, s->size(), s->data(), NULL, &result);
} else {
napi_create_string_utf8(env, s->data(), s->size(), &result);
Expand Down Expand Up @@ -830,15 +830,15 @@ struct Iterator final : public BaseIterator {
std::string* gt,
std::string* gte,
const bool fillCache,
const bool keyAsBuffer,
const bool valueAsBuffer,
const Encoding keyEncoding,
const Encoding valueEncoding,
const uint32_t highWaterMarkBytes)
: BaseIterator(database, reverse, lt, lte, gt, gte, limit, fillCache),
id_(id),
keys_(keys),
values_(values),
keyAsBuffer_(keyAsBuffer),
valueAsBuffer_(valueAsBuffer),
keyEncoding_(keyEncoding),
valueEncoding_(valueEncoding),
highWaterMarkBytes_(highWaterMarkBytes),
first_(true),
nexting_(false),
Expand Down Expand Up @@ -897,8 +897,8 @@ struct Iterator final : public BaseIterator {
const uint32_t id_;
const bool keys_;
const bool values_;
const bool keyAsBuffer_;
const bool valueAsBuffer_;
const Encoding keyEncoding_;
const Encoding valueEncoding_;
const uint32_t highWaterMarkBytes_;
bool first_;
bool nexting_;
Expand Down Expand Up @@ -1151,11 +1151,11 @@ struct GetWorker final : public PriorityWorker {
Database* database,
napi_value callback,
leveldb::Slice key,
const bool asBuffer,
const Encoding encoding,
const bool fillCache)
: PriorityWorker(env, database, callback, "classic_level.db.get"),
key_(key),
asBuffer_(asBuffer) {
encoding_(encoding) {
options_.fill_cache = fillCache;
}

Expand All @@ -1170,15 +1170,15 @@ struct GetWorker final : public PriorityWorker {
void HandleOKCallback (napi_env env, napi_value callback) override {
napi_value argv[2];
napi_get_null(env, &argv[0]);
Entry::Convert(env, &value_, asBuffer_, argv[1]);
Entry::Convert(env, &value_, encoding_, argv[1]);
CallFunction(env, callback, 2, argv);
}

private:
leveldb::ReadOptions options_;
leveldb::Slice key_;
std::string value_;
const bool asBuffer_;
const Encoding encoding_;
};

/**
Expand All @@ -1190,11 +1190,11 @@ NAPI_METHOD(db_get) {

leveldb::Slice key = ToSlice(env, argv[1]);
napi_value options = argv[2];
const bool asBuffer = EncodingIsBuffer(env, options, "valueEncoding");
const Encoding encoding = GetEncoding(env, options, "valueEncoding");
const bool fillCache = BooleanProperty(env, options, "fillCache", true);
napi_value callback = argv[3];

GetWorker* worker = new GetWorker(env, database, callback, key, asBuffer,
GetWorker* worker = new GetWorker(env, database, callback, key, encoding,
fillCache);
worker->Queue(env);

Expand All @@ -1209,10 +1209,10 @@ struct GetManyWorker final : public PriorityWorker {
Database* database,
std::vector<std::string> keys,
napi_value callback,
const bool valueAsBuffer,
const Encoding valueEncoding,
const bool fillCache)
: PriorityWorker(env, database, callback, "classic_level.get.many"),
keys_(std::move(keys)), valueAsBuffer_(valueAsBuffer) {
keys_(std::move(keys)), valueEncoding_(valueEncoding) {
options_.fill_cache = fillCache;
options_.snapshot = database->NewSnapshot();
}
Expand Down Expand Up @@ -1250,7 +1250,7 @@ struct GetManyWorker final : public PriorityWorker {
for (size_t idx = 0; idx < size; idx++) {
std::string* value = cache_[idx];
napi_value element;
Entry::Convert(env, value, valueAsBuffer_, element);
Entry::Convert(env, value, valueEncoding_, element);
napi_set_element(env, array, static_cast<uint32_t>(idx), element);
if (value != NULL) delete value;
}
Expand All @@ -1264,7 +1264,7 @@ struct GetManyWorker final : public PriorityWorker {
private:
leveldb::ReadOptions options_;
const std::vector<std::string> keys_;
const bool valueAsBuffer_;
const Encoding valueEncoding_;
std::vector<std::string*> cache_;
};

Expand All @@ -1277,12 +1277,12 @@ NAPI_METHOD(db_get_many) {

const auto keys = KeyArray(env, argv[1]);
napi_value options = argv[2];
const bool asBuffer = EncodingIsBuffer(env, options, "valueEncoding");
const Encoding valueEncoding = GetEncoding(env, options, "valueEncoding");
const bool fillCache = BooleanProperty(env, options, "fillCache", true);
napi_value callback = argv[3];

GetManyWorker* worker = new GetManyWorker(
env, database, keys, callback, asBuffer, fillCache
env, database, keys, callback, valueEncoding, fillCache
);

worker->Queue(env);
Expand Down Expand Up @@ -1626,8 +1626,8 @@ NAPI_METHOD(iterator_init) {
const bool keys = BooleanProperty(env, options, "keys", true);
const bool values = BooleanProperty(env, options, "values", true);
const bool fillCache = BooleanProperty(env, options, "fillCache", false);
const bool keyAsBuffer = EncodingIsBuffer(env, options, "keyEncoding");
const bool valueAsBuffer = EncodingIsBuffer(env, options, "valueEncoding");
const Encoding keyEncoding = GetEncoding(env, options, "keyEncoding");
const Encoding valueEncoding = GetEncoding(env, options, "valueEncoding");
const int limit = Int32Property(env, options, "limit", -1);
const uint32_t highWaterMarkBytes = Uint32Property(env, options, "highWaterMarkBytes", 16 * 1024);

Expand All @@ -1639,7 +1639,7 @@ NAPI_METHOD(iterator_init) {
const uint32_t id = database->currentIteratorId_++;
Iterator* iterator = new Iterator(database, id, reverse, keys,
values, limit, lt, lte, gt, gte, fillCache,
keyAsBuffer, valueAsBuffer, highWaterMarkBytes);
keyEncoding, valueEncoding, highWaterMarkBytes);
napi_value result;

NAPI_STATUS_THROWS(napi_create_external(env, iterator,
Expand Down Expand Up @@ -1757,12 +1757,12 @@ struct NextWorker final : public BaseWorker {
napi_value jsArray;
napi_create_array_with_length(env, size, &jsArray);

const bool kab = iterator_->keyAsBuffer_;
const bool vab = iterator_->valueAsBuffer_;
const Encoding ke = iterator_->keyEncoding_;
const Encoding ve = iterator_->valueEncoding_;

for (uint32_t idx = 0; idx < size; idx++) {
napi_value element;
iterator_->cache_[idx].ConvertByMode(env, Mode::entries, kab, vab, element);
iterator_->cache_[idx].ConvertByMode(env, Mode::entries, ke, ve, element);
napi_set_element(env, jsArray, idx, element);
}

Expand Down
2 changes: 1 addition & 1 deletion index.d.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,7 @@ import {
* @template VDefault The default type of values if not overridden on operations.
*/
declare class ClassicLevel<KDefault = string, VDefault = string>
extends AbstractLevel<string | Buffer, KDefault, VDefault> {
extends AbstractLevel<string | Buffer | Uint8Array, KDefault, VDefault> {
/**
* Database constructor.
*
Expand Down
3 changes: 2 additions & 1 deletion index.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,8 @@ class ClassicLevel extends AbstractLevel {
super({
encodings: {
buffer: true,
utf8: true
utf8: true,
view: true
},
seek: true,
createIfMissing: true,
Expand Down

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