go/src/internal/saferio/io.go

const chunk …

// ReadData reads n bytes from the input stream, but avoids allocating
// all n bytes if n is large. This avoids crashing the program by
// allocating all n bytes in cases where n is incorrect.
//
// The error is io.EOF only if no bytes were read.
// If an io.EOF happens after reading some but not all the bytes,
// ReadData returns io.ErrUnexpectedEOF.
func ReadData(r io.Reader, n uint64) ([]byte, error) { … }

// ReadDataAt reads n bytes from the input stream at off, but avoids
// allocating all n bytes if n is large. This avoids crashing the program
// by allocating all n bytes in cases where n is incorrect.
func ReadDataAt(r io.ReaderAt, n uint64, off int64) ([]byte, error) { … }

// SliceCapWithSize returns the capacity to use when allocating a slice.
// After the slice is allocated with the capacity, it should be
// built using append. This will avoid allocating too much memory
// if the capacity is large and incorrect.
//
// A negative result means that the value is always too big.
func SliceCapWithSize(size, c uint64) int { … }

// SliceCap is like SliceCapWithSize but using generics.
func SliceCap[E any](c uint64) int { … }