diff options
Diffstat (limited to 'vendor/github.com/go-redis/redis/v8/iterator.go')
-rw-r--r-- | vendor/github.com/go-redis/redis/v8/iterator.go | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/vendor/github.com/go-redis/redis/v8/iterator.go b/vendor/github.com/go-redis/redis/v8/iterator.go new file mode 100644 index 0000000000..2f8bc2beda --- /dev/null +++ b/vendor/github.com/go-redis/redis/v8/iterator.go @@ -0,0 +1,77 @@ +package redis + +import ( + "context" + "sync" +) + +// ScanIterator is used to incrementally iterate over a collection of elements. +// It's safe for concurrent use by multiple goroutines. +type ScanIterator struct { + mu sync.Mutex // protects Scanner and pos + cmd *ScanCmd + pos int +} + +// Err returns the last iterator error, if any. +func (it *ScanIterator) Err() error { + it.mu.Lock() + err := it.cmd.Err() + it.mu.Unlock() + return err +} + +// Next advances the cursor and returns true if more values can be read. +func (it *ScanIterator) Next(ctx context.Context) bool { + it.mu.Lock() + defer it.mu.Unlock() + + // Instantly return on errors. + if it.cmd.Err() != nil { + return false + } + + // Advance cursor, check if we are still within range. + if it.pos < len(it.cmd.page) { + it.pos++ + return true + } + + for { + // Return if there is no more data to fetch. + if it.cmd.cursor == 0 { + return false + } + + // Fetch next page. + switch it.cmd.args[0] { + case "scan", "qscan": + it.cmd.args[1] = it.cmd.cursor + default: + it.cmd.args[2] = it.cmd.cursor + } + + err := it.cmd.process(ctx, it.cmd) + if err != nil { + return false + } + + it.pos = 1 + + // Redis can occasionally return empty page. + if len(it.cmd.page) > 0 { + return true + } + } +} + +// Val returns the key/field at the current cursor position. +func (it *ScanIterator) Val() string { + var v string + it.mu.Lock() + if it.cmd.Err() == nil && it.pos > 0 && it.pos <= len(it.cmd.page) { + v = it.cmd.page[it.pos-1] + } + it.mu.Unlock() + return v +} |