summaryrefslogtreecommitdiff
path: root/src/database/database.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/database/database.cpp')
-rw-r--r--src/database/database.cpp219
1 files changed, 175 insertions, 44 deletions
diff --git a/src/database/database.cpp b/src/database/database.cpp
index df10ebb9..f5fe5240 100644
--- a/src/database/database.cpp
+++ b/src/database/database.cpp
@@ -2,9 +2,11 @@
#include <stdint.h>
+#include <algorithm>
#include <cstdint>
#include <functional>
#include <iomanip>
+#include <memory>
#include <sstream>
#include "esp_log.h"
@@ -216,6 +218,43 @@ auto Database::Update() -> std::future<void> {
});
}
+auto Database::GetSongs(std::size_t page_size) -> std::future<Result<Song>*> {
+ return RunOnDbTask<Result<Song>*>([=, this]() -> Result<Song>* {
+ Continuation<Song> c{.iterator = nullptr,
+ .prefix = CreateDataPrefix().data,
+ .start_key = CreateDataPrefix().data,
+ .forward = true,
+ .was_prev_forward = true,
+ .page_size = page_size};
+ return dbGetPage(c);
+ });
+}
+
+auto Database::GetDump(std::size_t page_size)
+ -> std::future<Result<std::string>*> {
+ return RunOnDbTask<Result<std::string>*>([=, this]() -> Result<std::string>* {
+ Continuation<std::string> c{.iterator = nullptr,
+ .prefix = "",
+ .start_key = "",
+ .forward = true,
+ .was_prev_forward = true,
+ .page_size = page_size};
+ return dbGetPage(c);
+ });
+}
+
+template <typename T>
+auto Database::GetPage(Continuation<T>* c) -> std::future<Result<T>*> {
+ Continuation<T> copy = *c;
+ return RunOnDbTask<Result<T>*>(
+ [=, this]() -> Result<T>* { return dbGetPage(copy); });
+}
+
+template auto Database::GetPage<Song>(Continuation<Song>* c)
+ -> std::future<Result<Song>*>;
+template auto Database::GetPage<std::string>(Continuation<std::string>* c)
+ -> std::future<Result<std::string>*>;
+
auto Database::dbMintNewSongId() -> SongId {
SongId next_id = 1;
std::string val;
@@ -287,37 +326,148 @@ auto Database::dbPutSong(SongId id,
dbPutHash(hash, id);
}
-auto parse_song(ITagParser* parser,
- const leveldb::Slice& key,
- const leveldb::Slice& value) -> std::optional<Song> {
- std::optional<SongData> data = ParseDataValue(value);
- if (!data) {
+template <typename T>
+auto Database::dbGetPage(const Continuation<T>& c) -> Result<T>* {
+ // Work out our starting point. Sometimes this will already done.
+ leveldb::Iterator* it = nullptr;
+ if (c.iterator != nullptr) {
+ it = c.iterator->release();
+ }
+ if (it == nullptr) {
+ it = db_->NewIterator(leveldb::ReadOptions());
+ it->Seek(c.start_key);
+ }
+
+ // Fix off-by-one if we just changed direction.
+ if (c.forward != c.was_prev_forward) {
+ if (c.forward) {
+ it->Next();
+ } else {
+ it->Prev();
+ }
+ }
+
+ // Grab results.
+ std::optional<std::string> first_key;
+ std::vector<T> records;
+ while (records.size() < c.page_size && it->Valid()) {
+ if (!it->key().starts_with(c.prefix)) {
+ break;
+ }
+ if (!first_key) {
+ first_key = it->key().ToString();
+ }
+ std::optional<T> parsed = ParseRecord<T>(it->key(), it->value());
+ if (parsed) {
+ records.push_back(*parsed);
+ }
+ if (c.forward) {
+ it->Next();
+ } else {
+ it->Prev();
+ }
+ }
+
+ std::unique_ptr<leveldb::Iterator> iterator(it);
+ if (iterator != nullptr) {
+ if (!iterator->Valid() || !it->key().starts_with(c.prefix)) {
+ iterator.reset();
+ }
+ }
+
+ // Put results into canonical order if we were iterating backwards.
+ if (!c.forward) {
+ std::reverse(records.begin(), records.end());
+ }
+
+ // Work out the new continuations.
+ std::optional<Continuation<T>> next_page;
+ if (c.forward) {
+ if (iterator != nullptr) {
+ // We were going forward, and now we want the next page. Re-use the
+ // existing iterator, and point the start key at it.
+ std::string key = iterator->key().ToString();
+ next_page = Continuation<T>{
+ .iterator = std::make_shared<std::unique_ptr<leveldb::Iterator>>(
+ std::move(iterator)),
+ .prefix = c.prefix,
+ .start_key = key,
+ .forward = true,
+ .was_prev_forward = true,
+ .page_size = c.page_size,
+ };
+ }
+ // No iterator means we ran out of results in this direction.
+ } else {
+ // We were going backwards, and now we want the next page. This is a
+ // reversal, to set the start key to the first record we saw and mark that
+ // it's off by one.
+ next_page = Continuation<T>{
+ .iterator = nullptr,
+ .prefix = c.prefix,
+ .start_key = *first_key,
+ .forward = true,
+ .was_prev_forward = false,
+ .page_size = c.page_size,
+ };
+ }
+
+ std::optional<Continuation<T>> prev_page;
+ if (c.forward) {
+ // We were going forwards, and now we want the previous page. Set the search
+ // key to the first result we saw, and mark that it's off by one.
+ prev_page = Continuation<T>{
+ .iterator = nullptr,
+ .prefix = c.prefix,
+ .start_key = *first_key,
+ .forward = false,
+ .was_prev_forward = true,
+ .page_size = c.page_size,
+ };
+ } else {
+ if (iterator != nullptr) {
+ // We were going backwards, and we still want to go backwards. The
+ // iterator is still valid.
+ std::string key = iterator->key().ToString();
+ prev_page = Continuation<T>{
+ .iterator = std::make_shared<std::unique_ptr<leveldb::Iterator>>(
+ std::move(iterator)),
+ .prefix = c.prefix,
+ .start_key = key,
+ .forward = false,
+ .was_prev_forward = false,
+ .page_size = c.page_size,
+ };
+ }
+ // No iterator means we ran out of results in this direction.
+ }
+
+ return new Result<T>(std::move(records), next_page, prev_page);
+}
+
+template auto Database::dbGetPage<Song>(const Continuation<Song>& c)
+ -> Result<Song>*;
+template auto Database::dbGetPage<std::string>(
+ const Continuation<std::string>& c) -> Result<std::string>*;
+
+template <>
+auto Database::ParseRecord<Song>(const leveldb::Slice& key,
+ const leveldb::Slice& val)
+ -> std::optional<Song> {
+ std::optional<SongData> data = ParseDataValue(val);
+ if (!data || data->is_tombstoned()) {
return {};
}
SongTags tags;
- if (!parser->ReadAndParseTags(data->filepath(), &tags)) {
+ if (!tag_parser_->ReadAndParseTags(data->filepath(), &tags)) {
return {};
}
return Song(*data, tags);
}
-auto Database::GetSongs(std::size_t page_size) -> std::future<Result<Song>> {
- return RunOnDbTask<Result<Song>>([=, this]() -> Result<Song> {
- return Query<Song>(CreateDataPrefix().slice, page_size,
- std::bind_front(&parse_song, tag_parser_));
- });
-}
-
-auto Database::GetMoreSongs(std::size_t page_size, Continuation c)
- -> std::future<Result<Song>> {
- leveldb::Iterator* it = c.release();
- return RunOnDbTask<Result<Song>>([=, this]() -> Result<Song> {
- return Query<Song>(it, page_size,
- std::bind_front(&parse_song, tag_parser_));
- });
-}
-
-auto parse_dump(const leveldb::Slice& key, const leveldb::Slice& value)
+template <>
+auto Database::ParseRecord<std::string>(const leveldb::Slice& key,
+ const leveldb::Slice& val)
-> std::optional<std::string> {
std::ostringstream stream;
stream << "key: ";
@@ -335,33 +485,14 @@ auto parse_dump(const leveldb::Slice& key, const leveldb::Slice& value)
<< static_cast<int>(str[i]);
}
}
- for (std::size_t i = 2; i < str.size(); i++) {
- }
}
stream << "\tval: 0x";
- std::string str = value.ToString();
- for (int i = 0; i < value.size(); i++) {
+ std::string str = val.ToString();
+ for (int i = 0; i < val.size(); i++) {
stream << std::hex << std::setfill('0') << std::setw(2)
<< static_cast<int>(str[i]);
}
return stream.str();
}
-auto Database::GetDump(std::size_t page_size)
- -> std::future<Result<std::string>> {
- leveldb::Iterator* it = db_->NewIterator(leveldb::ReadOptions());
- it->SeekToFirst();
- return RunOnDbTask<Result<std::string>>([=, this]() -> Result<std::string> {
- return Query<std::string>(it, page_size, &parse_dump);
- });
-}
-
-auto Database::GetMoreDump(std::size_t page_size, Continuation c)
- -> std::future<Result<std::string>> {
- leveldb::Iterator* it = c.release();
- return RunOnDbTask<Result<std::string>>([=, this]() -> Result<std::string> {
- return Query<std::string>(it, page_size, &parse_dump);
- });
-}
-
} // namespace database
generated by cgit v1.2.3 (git 2.25.1) at 2026-04-29 19:27:53 +0000