diff options
Diffstat (limited to 'utils')
-rw-r--r-- | utils/ioutil/common.go | 18 | ||||
-rw-r--r-- | utils/ioutil/common_test.go | 23 | ||||
-rw-r--r-- | utils/merkletrie/internal/frame/frame.go | 91 | ||||
-rw-r--r-- | utils/merkletrie/internal/frame/frame_test.go | 108 | ||||
-rw-r--r-- | utils/merkletrie/iter.go | 212 | ||||
-rw-r--r-- | utils/merkletrie/iter_test.go | 462 |
6 files changed, 900 insertions, 14 deletions
diff --git a/utils/ioutil/common.go b/utils/ioutil/common.go index a847abd..73cc9c3 100644 --- a/utils/ioutil/common.go +++ b/utils/ioutil/common.go @@ -1,3 +1,4 @@ +// Package ioutil implements some I/O utility functions. package ioutil import ( @@ -63,20 +64,9 @@ func WriteNopCloser(w io.Writer) io.WriteCloser { return writeNopCloser{w} } -// CheckClose is used with defer to close the given io.Closer and check its -// returned error value. If Close returns an error and the given *error -// is not nil, *error is set to the error returned by Close. -// -// CheckClose is typically used with named return values like so: -// -// func do(obj *Object) (err error) { -// w, err := obj.Writer() -// if err != nil { -// return nil -// } -// defer CheckClose(w, &err) -// // work with w -// } +// CheckClose calls Close on the given io.Closer. If the given *error points to +// nil, it will be assigned the error returned by Close. Otherwise, any error +// returned by Close will be ignored. CheckClose is usually called with defer. func CheckClose(c io.Closer, err *error) { if cerr := c.Close(); cerr != nil && *err == nil { *err = cerr diff --git a/utils/ioutil/common_test.go b/utils/ioutil/common_test.go index f5017f7..2d6ef80 100644 --- a/utils/ioutil/common_test.go +++ b/utils/ioutil/common_test.go @@ -3,6 +3,7 @@ package ioutil import ( "bytes" "io/ioutil" + "strings" "testing" . "gopkg.in/check.v1" @@ -53,3 +54,25 @@ func (s *CommonSuite) TestNewReadCloser(c *C) { c.Assert(r.Close(), IsNil) c.Assert(closer.called, Equals, 1) } + +func ExampleCheckClose() { + // CheckClose is commonly used with named return values + f := func() (err error) { + // Get a io.ReadCloser + r := ioutil.NopCloser(strings.NewReader("foo")) + + // defer CheckClose call with an io.Closer and pointer to error + defer CheckClose(r, &err) + + // ... work with r ... + + // if err is not nil, CheckClose will assign any close errors to it + return err + + } + + err := f() + if err != nil { + panic(err) + } +} diff --git a/utils/merkletrie/internal/frame/frame.go b/utils/merkletrie/internal/frame/frame.go new file mode 100644 index 0000000..fd06307 --- /dev/null +++ b/utils/merkletrie/internal/frame/frame.go @@ -0,0 +1,91 @@ +package frame + +import ( + "bytes" + "fmt" + "sort" + "strings" + + "srcd.works/go-git.v4/utils/merkletrie/noder" +) + +// A Frame is a collection of siblings in a trie, sorted alphabetically +// by name. +type Frame struct { + // siblings, sorted in reverse alphabetical order by name + stack []noder.Noder +} + +type byName []noder.Noder + +func (a byName) Len() int { return len(a) } +func (a byName) Swap(i, j int) { a[i], a[j] = a[j], a[i] } +func (a byName) Less(i, j int) bool { + return strings.Compare(a[i].Name(), a[j].Name()) < 0 +} + +// New returns a frame with the children of the provided node. +func New(n noder.Noder) (*Frame, error) { + children, err := n.Children() + if err != nil { + return nil, err + } + + sort.Sort(sort.Reverse(byName(children))) + return &Frame{ + stack: children, + }, nil +} + +// String returns the quoted names of the noders in the frame sorted in +// alphabeticall order by name, surrounded by square brackets and +// separated by comas. +// +// Examples: +// [] +// ["a", "b"] +func (f *Frame) String() string { + var buf bytes.Buffer + _ = buf.WriteByte('[') + + sep := "" + for i := f.Len() - 1; i >= 0; i-- { + _, _ = buf.WriteString(sep) + sep = ", " + _, _ = buf.WriteString(fmt.Sprintf("%q", f.stack[i].Name())) + } + + _ = buf.WriteByte(']') + + return buf.String() +} + +// First returns, but dont extract, the noder with the alphabetically +// smaller name in the frame and true if the frame was not empy. +// Otherwise it returns nil and false. +func (f *Frame) First() (noder.Noder, bool) { + if f.Len() == 0 { + return nil, false + } + + top := f.Len() - 1 + + return f.stack[top], true +} + +// Drop extracts the noder with the alphabetically smaller name in the +// frame or does nothing if the frame was empty. +func (f *Frame) Drop() { + if f.Len() == 0 { + return + } + + top := f.Len() - 1 + f.stack[top] = nil + f.stack = f.stack[:top] +} + +// Len returns the number of noders in the frame. +func (f *Frame) Len() int { + return len(f.stack) +} diff --git a/utils/merkletrie/internal/frame/frame_test.go b/utils/merkletrie/internal/frame/frame_test.go new file mode 100644 index 0000000..9cc0994 --- /dev/null +++ b/utils/merkletrie/internal/frame/frame_test.go @@ -0,0 +1,108 @@ +package frame + +import ( + "fmt" + "testing" + + "srcd.works/go-git.v4/utils/merkletrie/internal/fsnoder" + "srcd.works/go-git.v4/utils/merkletrie/noder" + + . "gopkg.in/check.v1" +) + +func Test(t *testing.T) { TestingT(t) } + +type FrameSuite struct{} + +var _ = Suite(&FrameSuite{}) + +func (s *FrameSuite) TestNewFrameFromEmptyDir(c *C) { + A, err := fsnoder.New("A()") + c.Assert(err, IsNil) + + frame, err := New(A) + c.Assert(err, IsNil) + + expectedString := `[]` + c.Assert(frame.String(), Equals, expectedString) + + first, ok := frame.First() + c.Assert(first, IsNil) + c.Assert(ok, Equals, false) + + first, ok = frame.First() + c.Assert(first, IsNil) + c.Assert(ok, Equals, false) + + l := frame.Len() + c.Assert(l, Equals, 0) +} + +func (s *FrameSuite) TestNewFrameFromNonEmpty(c *C) { + // _______A/________ + // | / \ | + // x y B/ C/ + // | + // z + root, err := fsnoder.New("A(x<> y<> B() C(z<>))") + c.Assert(err, IsNil) + frame, err := New(root) + c.Assert(err, IsNil) + + expectedString := `["B", "C", "x", "y"]` + c.Assert(frame.String(), Equals, expectedString) + + l := frame.Len() + c.Assert(l, Equals, 4) + + checkFirstAndDrop(c, frame, "B", true) + l = frame.Len() + c.Assert(l, Equals, 3) + + checkFirstAndDrop(c, frame, "C", true) + l = frame.Len() + c.Assert(l, Equals, 2) + + checkFirstAndDrop(c, frame, "x", true) + l = frame.Len() + c.Assert(l, Equals, 1) + + checkFirstAndDrop(c, frame, "y", true) + l = frame.Len() + c.Assert(l, Equals, 0) + + checkFirstAndDrop(c, frame, "", false) + l = frame.Len() + c.Assert(l, Equals, 0) + + checkFirstAndDrop(c, frame, "", false) +} + +func checkFirstAndDrop(c *C, f *Frame, expectedNodeName string, expectedOK bool) { + first, ok := f.First() + c.Assert(ok, Equals, expectedOK) + if expectedOK { + c.Assert(first.Name(), Equals, expectedNodeName) + } + + f.Drop() +} + +// a mock noder that returns error when Children() is called +type errorNoder struct{} + +func (e *errorNoder) Hash() []byte { return nil } +func (e *errorNoder) Name() string { return "" } +func (e *errorNoder) String() string { return "" } +func (e *errorNoder) IsDir() bool { return true } +func (e *errorNoder) Children() ([]noder.Noder, error) { + return nil, fmt.Errorf("mock error") +} +func (e *errorNoder) NumChildren() (int, error) { + return 0, fmt.Errorf("mock error") +} + +func (s *FrameSuite) TestNewFrameErrors(c *C) { + _, err := New(&errorNoder{}) + c.Assert(err, Not(IsNil)) +} diff --git a/utils/merkletrie/iter.go b/utils/merkletrie/iter.go new file mode 100644 index 0000000..44cba70 --- /dev/null +++ b/utils/merkletrie/iter.go @@ -0,0 +1,212 @@ +package merkletrie + +import ( + "fmt" + "io" + + "srcd.works/go-git.v4/utils/merkletrie/internal/frame" + "srcd.works/go-git.v4/utils/merkletrie/noder" +) + +// Iter is an iterator for merkletries (only the trie part of the +// merkletrie is relevant here, it does not use the Hasher interface). +// +// The iteration is performed in depth-first pre-order. Entries at each +// depth are traversed in (case-sensitive) alphabetical order. +// +// This is the kind of traversal you will expect when listing ordinary +// files and directories recursively, for example: +// +// Trie Traversal order +// ---- --------------- +// . +// / | \ c +// / | \ d/ +// d c z ===> d/a +// / \ d/b +// b a z +// +// +// This iterator is somewhat especial as you can chose to skip whole +// "directories" when iterating: +// +// - The Step method will iterate normally. +// +// - the Next method will not descend deeper into the tree. +// +// For example, if the iterator is at `d/`, the Step method will return +// `d/a` while the Next would have returned `z` instead (skipping `d/` +// and its descendants). The name of the these two methods are based on +// the well known "next" and "step" operations, quite common in +// debuggers, like gdb. +// +// The paths returned by the iterator will be relative, if the iterator +// was created from a single node, or absolute, if the iterator was +// created from the path to the node (the path will be prefixed to all +// returned paths). +type Iter struct { + // Tells if the iteration has started. + hasStarted bool + // The top of this stack has the current node and its siblings. The + // rest of the stack keeps the ancestors of the current node and + // their corresponding siblings. The current element is always the + // top element of the top frame. + // + // When "step"ping into a node, its children are pushed as a new + // frame. + // + // When "next"ing pass a node, the current element is dropped by + // popping the top frame. + frameStack []*frame.Frame + // The base path used to turn the relative paths used internally by + // the iterator into absolute paths used by external applications. + // For relative iterator this will be nil. + base noder.Path +} + +// NewIter returns a new relative iterator using the provider noder as +// its unnamed root. When iterating, all returned paths will be +// relative to node. +func NewIter(n noder.Noder) (*Iter, error) { + return newIter(n, nil) +} + +// NewIterFromPath returns a new absolute iterator from the noder at the +// end of the path p. When iterating, all returned paths will be +// absolute, using the root of the path p as their root. +func NewIterFromPath(p noder.Path) (*Iter, error) { + return newIter(p, p) // Path implements Noder +} + +func newIter(root noder.Noder, base noder.Path) (*Iter, error) { + ret := &Iter{ + base: base, + } + + frame, err := frame.New(root) + if err != nil { + return nil, err + } + ret.push(frame) + + return ret, nil +} + +func (iter *Iter) top() (*frame.Frame, bool) { + if len(iter.frameStack) == 0 { + return nil, false + } + top := len(iter.frameStack) - 1 + + return iter.frameStack[top], true +} + +func (iter *Iter) push(f *frame.Frame) { + iter.frameStack = append(iter.frameStack, f) +} + +const ( + doDescend = true + dontDescend = false +) + +// Next returns the path of the next node without descending deeper into +// the trie and nil. If there are no more entries in the trie it +// returns nil and io.EOF. In case of error, it will return nil and the +// error. +func (iter *Iter) Next() (noder.Path, error) { + return iter.advance(dontDescend) +} + +// Step returns the path to the next node in the trie, descending deeper +// into it if needed, and nil. If there are no more nodes in the trie, +// it returns nil and io.EOF. In case of error, it will return nil and +// the error. +func (iter *Iter) Step() (noder.Path, error) { + return iter.advance(doDescend) +} + +// Advances the iterator in the desired direction: descend or +// dontDescend. +// +// Returns the new current element and a nil error on success. If there +// are no more elements in the trie below the base, it returns nil, and +// io.EOF. Returns nil and an error in case of errors. +func (iter *Iter) advance(wantDescend bool) (noder.Path, error) { + current, err := iter.current() + if err != nil { + return nil, err + } + + // The first time we just return the current node. + if !iter.hasStarted { + iter.hasStarted = true + return current, nil + } + + // Advances means getting a next current node, either its first child or + // its next sibling, depending if we must descend or not. + numChildren, err := current.NumChildren() + if err != nil { + return nil, err + } + + mustDescend := numChildren != 0 && wantDescend + if mustDescend { + // descend: add a new frame with the current's children. + frame, err := frame.New(current) + if err != nil { + return nil, err + } + iter.push(frame) + } else { + // don't descend: just drop the current node + iter.drop() + } + + return iter.current() +} + +// Returns the path to the current node, adding the base if there was +// one, and a nil error. If there were no noders left, it returns nil +// and io.EOF. If an error occurred, it returns nil and the error. +func (iter *Iter) current() (noder.Path, error) { + if topFrame, ok := iter.top(); !ok { + return nil, io.EOF + } else if _, ok := topFrame.First(); !ok { + return nil, io.EOF + } + + ret := make(noder.Path, 0, len(iter.base)+len(iter.frameStack)) + + // concat the base... + ret = append(ret, iter.base...) + // ... and the current node and all its ancestors + for i, f := range iter.frameStack { + t, ok := f.First() + if !ok { + panic(fmt.Sprintf("frame %d is empty", i)) + } + ret = append(ret, t) + } + + return ret, nil +} + +// removes the current node if any, and all the frames that become empty as a +// consecuence of this action. +func (iter *Iter) drop() { + frame, ok := iter.top() + if !ok { + return + } + + frame.Drop() + // if the frame is empty, remove it and its parent, recursively + if frame.Len() == 0 { + top := len(iter.frameStack) - 1 + iter.frameStack[top] = nil + iter.frameStack = iter.frameStack[:top] + iter.drop() + } +} diff --git a/utils/merkletrie/iter_test.go b/utils/merkletrie/iter_test.go new file mode 100644 index 0000000..52d567a --- /dev/null +++ b/utils/merkletrie/iter_test.go @@ -0,0 +1,462 @@ +package merkletrie_test + +import ( + "fmt" + "io" + "strings" + "testing" + + "srcd.works/go-git.v4/utils/merkletrie" + "srcd.works/go-git.v4/utils/merkletrie/internal/fsnoder" + "srcd.works/go-git.v4/utils/merkletrie/noder" + + . "gopkg.in/check.v1" +) + +func Test(t *testing.T) { TestingT(t) } + +type IterSuite struct{} + +var _ = Suite(&IterSuite{}) + +// A test is a list of operations we want to perform on an iterator and +// their expected results. +// +// The operations are expresed as a sequence of `n` and `s`, +// representing the amount of next and step operations we want to call +// on the iterator and their order. For example, an operations value of +// "nns" means: call a `n`ext, then another `n`ext and finish with a +// `s`tep. +// +// The expeced is the full path of the noders returned by the +// operations, separated by spaces. +// +// For instance: +// +// t := test{ +// operations: "ns", +// expected: "a a/b" +// } +// +// means: +// +// - the first iterator operation has to be Next, and it must return a +// node called "a" with no ancestors. +// +// - the second operation has to be Step, and it must return a node +// called "b" with a single ancestor called "a". +type test struct { + operations string + expected string +} + +// Runs a test on the provided iterator, checking that the names of the +// returned values are correct. If not, the treeDescription value is +// printed along with information about mismatch. +func (t test) run(c *C, iter *merkletrie.Iter, + treeDescription string, testNumber int) { + + expectedChunks := strings.Split(t.expected, " ") + if t.expected == "" { + expectedChunks = []string{} + } + + if len(t.operations) < len(expectedChunks) { + c.Fatalf("malformed test %d: not enough operations", testNumber) + return + } + + var obtained noder.Path + var err error + for i := range t.operations { + comment := Commentf("\ntree: %q\ntest #%d (%q)\noperation #%d (%q)", + treeDescription, testNumber, t.operations, i, t.operations[i]) + + switch t.operations[i] { + case 'n': + obtained, err = iter.Next() + if err != io.EOF { + c.Assert(err, IsNil) + } + case 's': + obtained, err = iter.Step() + if err != io.EOF { + c.Assert(err, IsNil) + } + default: + c.Fatalf("unknown operation at test %d, operation %d (%s)\n", + testNumber, i, t.operations[i]) + } + if i >= len(expectedChunks) { + c.Assert(err, Equals, io.EOF, comment) + continue + } + + c.Assert(err, IsNil, comment) + c.Assert(obtained.String(), Equals, expectedChunks[i], comment) + } +} + +// A testsCollection value represents a tree and a collection of tests +// we want to perfrom on iterators of that tree. +// +// Example: +// +// . +// | +// --------- +// | | | +// a b c +// | +// z +// +// var foo testCollection = { +// tree: "(a<> b(z<>) c<>)" +// tests: []test{ +// {operations: "nns", expected: "a b b/z"}, +// {operations: "nnn", expected: "a b c"}, +// }, +// } +// +// A new iterator will be build for each test. +type testsCollection struct { + tree string // a fsnoder description of a tree. + tests []test // the collection of tests we want to run +} + +// Executes all the tests in a testsCollection. +func (tc testsCollection) run(c *C) { + root, err := fsnoder.New(tc.tree) + c.Assert(err, IsNil) + + for i, t := range tc.tests { + iter, err := merkletrie.NewIter(root) + c.Assert(err, IsNil) + t.run(c, iter, root.String(), i) + } +} + +func (s *IterSuite) TestEmptyNamedDir(c *C) { + tc := testsCollection{ + tree: "A()", + tests: []test{ + {operations: "n", expected: ""}, + {operations: "nn", expected: ""}, + {operations: "nnn", expected: ""}, + {operations: "nnns", expected: ""}, + {operations: "nnnssnsnns", expected: ""}, + {operations: "s", expected: ""}, + {operations: "ss", expected: ""}, + {operations: "sss", expected: ""}, + {operations: "sssn", expected: ""}, + {operations: "sssnnsnssn", expected: ""}, + }, + } + tc.run(c) +} + +func (s *IterSuite) TestEmptyUnnamedDir(c *C) { + tc := testsCollection{ + tree: "()", + tests: []test{ + {operations: "n", expected: ""}, + {operations: "nn", expected: ""}, + {operations: "nnn", expected: ""}, + {operations: "nnns", expected: ""}, + {operations: "nnnssnsnns", expected: ""}, + {operations: "s", expected: ""}, + {operations: "ss", expected: ""}, + {operations: "sss", expected: ""}, + {operations: "sssn", expected: ""}, + {operations: "sssnnsnssn", expected: ""}, + }, + } + tc.run(c) +} + +func (s *IterSuite) TestOneFile(c *C) { + tc := testsCollection{ + tree: "(a<>)", + tests: []test{ + {operations: "n", expected: "a"}, + {operations: "nn", expected: "a"}, + {operations: "nnn", expected: "a"}, + {operations: "nnns", expected: "a"}, + {operations: "nnnssnsnns", expected: "a"}, + {operations: "s", expected: "a"}, + {operations: "ss", expected: "a"}, + {operations: "sss", expected: "a"}, + {operations: "sssn", expected: "a"}, + {operations: "sssnnsnssn", expected: "a"}, + }, + } + tc.run(c) +} + +// root +// / \ +// a b +func (s *IterSuite) TestTwoFiles(c *C) { + tc := testsCollection{ + tree: "(a<> b<>)", + tests: []test{ + {operations: "nnn", expected: "a b"}, + {operations: "nns", expected: "a b"}, + {operations: "nsn", expected: "a b"}, + {operations: "nss", expected: "a b"}, + {operations: "snn", expected: "a b"}, + {operations: "sns", expected: "a b"}, + {operations: "ssn", expected: "a b"}, + {operations: "sss", expected: "a b"}, + }, + } + tc.run(c) +} + +// root +// | +// a +// | +// b +func (s *IterSuite) TestDirWithFile(c *C) { + tc := testsCollection{ + tree: "(a(b<>))", + tests: []test{ + {operations: "nnn", expected: "a"}, + {operations: "nns", expected: "a"}, + {operations: "nsn", expected: "a a/b"}, + {operations: "nss", expected: "a a/b"}, + {operations: "snn", expected: "a"}, + {operations: "sns", expected: "a"}, + {operations: "ssn", expected: "a a/b"}, + {operations: "sss", expected: "a a/b"}, + }, + } + tc.run(c) +} + +// root +// /|\ +// c a b +func (s *IterSuite) TestThreeSiblings(c *C) { + tc := testsCollection{ + tree: "(c<> a<> b<>)", + tests: []test{ + {operations: "nnnn", expected: "a b c"}, + {operations: "nnns", expected: "a b c"}, + {operations: "nnsn", expected: "a b c"}, + {operations: "nnss", expected: "a b c"}, + {operations: "nsnn", expected: "a b c"}, + {operations: "nsns", expected: "a b c"}, + {operations: "nssn", expected: "a b c"}, + {operations: "nsss", expected: "a b c"}, + {operations: "snnn", expected: "a b c"}, + {operations: "snns", expected: "a b c"}, + {operations: "snsn", expected: "a b c"}, + {operations: "snss", expected: "a b c"}, + {operations: "ssnn", expected: "a b c"}, + {operations: "ssns", expected: "a b c"}, + {operations: "sssn", expected: "a b c"}, + {operations: "ssss", expected: "a b c"}, + }, + } + tc.run(c) +} + +// root +// | +// b +// | +// c +// | +// a +func (s *IterSuite) TestThreeVertical(c *C) { + tc := testsCollection{ + tree: "(b(c(a())))", + tests: []test{ + {operations: "nnnn", expected: "b"}, + {operations: "nnns", expected: "b"}, + {operations: "nnsn", expected: "b"}, + {operations: "nnss", expected: "b"}, + {operations: "nsnn", expected: "b b/c"}, + {operations: "nsns", expected: "b b/c"}, + {operations: "nssn", expected: "b b/c b/c/a"}, + {operations: "nsss", expected: "b b/c b/c/a"}, + {operations: "snnn", expected: "b"}, + {operations: "snns", expected: "b"}, + {operations: "snsn", expected: "b"}, + {operations: "snss", expected: "b"}, + {operations: "ssnn", expected: "b b/c"}, + {operations: "ssns", expected: "b b/c"}, + {operations: "sssn", expected: "b b/c b/c/a"}, + {operations: "ssss", expected: "b b/c b/c/a"}, + }, + } + tc.run(c) +} + +// root +// / \ +// c a +// | +// b +func (s *IterSuite) TestThreeMix1(c *C) { + tc := testsCollection{ + tree: "(c(b<>) a<>)", + tests: []test{ + {operations: "nnnn", expected: "a c"}, + {operations: "nnns", expected: "a c"}, + {operations: "nnsn", expected: "a c c/b"}, + {operations: "nnss", expected: "a c c/b"}, + {operations: "nsnn", expected: "a c"}, + {operations: "nsns", expected: "a c"}, + {operations: "nssn", expected: "a c c/b"}, + {operations: "nsss", expected: "a c c/b"}, + {operations: "snnn", expected: "a c"}, + {operations: "snns", expected: "a c"}, + {operations: "snsn", expected: "a c c/b"}, + {operations: "snss", expected: "a c c/b"}, + {operations: "ssnn", expected: "a c"}, + {operations: "ssns", expected: "a c"}, + {operations: "sssn", expected: "a c c/b"}, + {operations: "ssss", expected: "a c c/b"}, + }, + } + tc.run(c) +} + +// root +// / \ +// b a +// | +// c +func (s *IterSuite) TestThreeMix2(c *C) { + tc := testsCollection{ + tree: "(b() a(c<>))", + tests: []test{ + {operations: "nnnn", expected: "a b"}, + {operations: "nnns", expected: "a b"}, + {operations: "nnsn", expected: "a b"}, + {operations: "nnss", expected: "a b"}, + {operations: "nsnn", expected: "a a/c b"}, + {operations: "nsns", expected: "a a/c b"}, + {operations: "nssn", expected: "a a/c b"}, + {operations: "nsss", expected: "a a/c b"}, + {operations: "snnn", expected: "a b"}, + {operations: "snns", expected: "a b"}, + {operations: "snsn", expected: "a b"}, + {operations: "snss", expected: "a b"}, + {operations: "ssnn", expected: "a a/c b"}, + {operations: "ssns", expected: "a a/c b"}, + {operations: "sssn", expected: "a a/c b"}, + {operations: "ssss", expected: "a a/c b"}, + }, + } + tc.run(c) +} + +// root +// / | \ +// / | ---- +// f d h -------- +// /\ / \ | +// e a j b/ g +// | / \ | +// l n k icm +// | +// o +// | +// p/ +func (s *IterSuite) TestCrazy(c *C) { + tc := testsCollection{ + tree: "(f(e(l<>) a(n(o(p())) k<>)) d<> h(j(i<> c<> m<>) b() g<>))", + tests: []test{ + {operations: "nnnnn", expected: "d f h"}, + {operations: "nnnns", expected: "d f h"}, + {operations: "nnnsn", expected: "d f h h/b h/g"}, + {operations: "nnnss", expected: "d f h h/b h/g"}, + {operations: "nnsnn", expected: "d f f/a f/e h"}, + {operations: "nnsns", expected: "d f f/a f/e f/e/l"}, + {operations: "nnssn", expected: "d f f/a f/a/k f/a/n"}, + {operations: "nnsss", expected: "d f f/a f/a/k f/a/n"}, + {operations: "nsnnn", expected: "d f h"}, + {operations: "nsnns", expected: "d f h"}, + {operations: "nsnsn", expected: "d f h h/b h/g"}, + {operations: "nsnss", expected: "d f h h/b h/g"}, + {operations: "nssnn", expected: "d f f/a f/e h"}, + }, + } + tc.run(c) +} + +// . +// | +// a +// | +// b +// / \ +// z h +// / \ +// d e +// | +// f +func (s *IterSuite) TestNewIterFromPath(c *C) { + tree, err := fsnoder.New("(a(b(z(d<> e(f<>)) h<>)))") + c.Assert(err, IsNil) + + z := find(c, tree, "z") + + iter, err := merkletrie.NewIterFromPath(z) + c.Assert(err, IsNil) + + n, err := iter.Next() + c.Assert(err, IsNil) + c.Assert(n.String(), Equals, "a/b/z/d") + + n, err = iter.Next() + c.Assert(err, IsNil) + c.Assert(n.String(), Equals, "a/b/z/e") + + n, err = iter.Step() + c.Assert(err, IsNil) + c.Assert(n.String(), Equals, "a/b/z/e/f") + + _, err = iter.Step() + c.Assert(err, Equals, io.EOF) +} + +func find(c *C, tree noder.Noder, name string) noder.Path { + iter, err := merkletrie.NewIter(tree) + c.Assert(err, IsNil) + + for { + current, err := iter.Step() + if err != io.EOF { + c.Assert(err, IsNil) + } else { + c.Fatalf("node %s not found in tree %s", name, tree) + } + + if current.Name() == name { + return current + } + } +} + +type errorNoder struct{} + +func (e *errorNoder) Name() string { return "" } +func (e *errorNoder) String() string { return "" } +func (e *errorNoder) Hash() []byte { return nil } +func (e *errorNoder) IsDir() bool { return true } +func (e *errorNoder) Children() ([]noder.Noder, error) { + return nil, fmt.Errorf("mock error") +} +func (e *errorNoder) NumChildren() (int, error) { + return 0, fmt.Errorf("mock error") +} + +func (s *IterSuite) TestNewIterFailsOnChildrenErrors(c *C) { + _, err := merkletrie.NewIter(&errorNoder{}) + c.Assert(err, Not(IsNil)) +} |