Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

libs: remove useless code in group #3504

Merged
merged 3 commits into from
Mar 29, 2019
Merged

libs: remove useless code in group #3504

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
76a9663
lib: remove useless code in group
unclezoro Mar 28, 2019
9498c49
update change log
unclezoro Mar 29, 2019
ac2e56a
Update CHANGELOG_PENDING.md
liamsi Mar 29, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
1 change: 1 addition & 0 deletions CHANGELOG_PENDING.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@
* Apps

* Go API
- [libs/autofile] Remove useless code in autofile package
unclezoro marked this conversation as resolved.
Show resolved Hide resolved

* Blockchain Protocol

Expand Down
251 changes: 0 additions & 251 deletions libs/autofile/group.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -331,172 +331,6 @@ func (g *Group) NewReader(index int) (*GroupReader, error) {
return r, nil
}

// Returns -1 if line comes after, 0 if found, 1 if line comes before.
type SearchFunc func(line string) (int, error)

// Searches for the right file in Group, then returns a GroupReader to start
// streaming lines.
// Returns true if an exact match was found, otherwise returns the next greater
// line that starts with prefix.
// CONTRACT: Caller must close the returned GroupReader
func (g *Group) Search(prefix string, cmp SearchFunc) (*GroupReader, bool, error) {
g.mtx.Lock()
minIndex, maxIndex := g.minIndex, g.maxIndex
g.mtx.Unlock()
// Now minIndex/maxIndex may change meanwhile,
// but it shouldn't be a big deal
// (maybe we'll want to limit scanUntil though)

for {
curIndex := (minIndex + maxIndex + 1) / 2

// Base case, when there's only 1 choice left.
if minIndex == maxIndex {
r, err := g.NewReader(maxIndex)
if err != nil {
return nil, false, err
}
match, err := scanUntil(r, prefix, cmp)
if err != nil {
r.Close()
return nil, false, err
}
return r, match, err
}

// Read starting roughly at the middle file,
// until we find line that has prefix.
r, err := g.NewReader(curIndex)
if err != nil {
return nil, false, err
}
foundIndex, line, err := scanNext(r, prefix)
r.Close()
if err != nil {
return nil, false, err
}

// Compare this line to our search query.
val, err := cmp(line)
if err != nil {
return nil, false, err
}
if val < 0 {
// Line will come later
minIndex = foundIndex
} else if val == 0 {
// Stroke of luck, found the line
r, err := g.NewReader(foundIndex)
if err != nil {
return nil, false, err
}
match, err := scanUntil(r, prefix, cmp)
if !match {
panic("Expected match to be true")
}
if err != nil {
r.Close()
return nil, false, err
}
return r, true, err
} else {
// We passed it
maxIndex = curIndex - 1
}
}

}

// Scans and returns the first line that starts with 'prefix'
// Consumes line and returns it.
func scanNext(r *GroupReader, prefix string) (int, string, error) {
for {
line, err := r.ReadLine()
if err != nil {
return 0, "", err
}
if !strings.HasPrefix(line, prefix) {
continue
}
index := r.CurIndex()
return index, line, nil
}
}

// Returns true iff an exact match was found.
// Pushes line, does not consume it.
func scanUntil(r *GroupReader, prefix string, cmp SearchFunc) (bool, error) {
for {
line, err := r.ReadLine()
if err != nil {
return false, err
}
if !strings.HasPrefix(line, prefix) {
continue
}
val, err := cmp(line)
if err != nil {
return false, err
}
if val < 0 {
continue
} else if val == 0 {
r.PushLine(line)
return true, nil
} else {
r.PushLine(line)
return false, nil
}
}
}

// Searches backwards for the last line in Group with prefix.
// Scans each file forward until the end to find the last match.
func (g *Group) FindLast(prefix string) (match string, found bool, err error) {
g.mtx.Lock()
minIndex, maxIndex := g.minIndex, g.maxIndex
g.mtx.Unlock()

r, err := g.NewReader(maxIndex)
if err != nil {
return "", false, err
}
defer r.Close()

// Open files from the back and read
GROUP_LOOP:
for i := maxIndex; i >= minIndex; i-- {
err := r.SetIndex(i)
if err != nil {
return "", false, err
}
// Scan each line and test whether line matches
for {
line, err := r.ReadLine()
if err == io.EOF {
if found {
return match, found, nil
}
continue GROUP_LOOP
} else if err != nil {
return "", false, err
}
if strings.HasPrefix(line, prefix) {
match = line
found = true
}
if r.CurIndex() > i {
if found {
return match, found, nil
}
continue GROUP_LOOP
}
}
}

return
}

// GroupInfo holds information about the group.
type GroupInfo struct {
MinIndex int // index of the first file in the group, including head
Expand Down Expand Up @@ -654,48 +488,6 @@ func (gr *GroupReader) Read(p []byte) (n int, err error) {
}
}

// ReadLine reads a line (without delimiter).
// just return io.EOF if no new lines found.
func (gr *GroupReader) ReadLine() (string, error) {
gr.mtx.Lock()
defer gr.mtx.Unlock()

// From PushLine
if gr.curLine != nil {
line := string(gr.curLine)
gr.curLine = nil
return line, nil
}

// Open file if not open yet
if gr.curReader == nil {
err := gr.openFile(gr.curIndex)
if err != nil {
return "", err
}
}

// Iterate over files until line is found
var linePrefix string
for {
bytesRead, err := gr.curReader.ReadBytes('\n')
if err == io.EOF {
// Open the next file
if err1 := gr.openFile(gr.curIndex + 1); err1 != nil {
return "", err1
}
if len(bytesRead) > 0 && bytesRead[len(bytesRead)-1] == byte('\n') {
return linePrefix + string(bytesRead[:len(bytesRead)-1]), nil
}
linePrefix += string(bytesRead)
continue
} else if err != nil {
return "", err
}
return linePrefix + string(bytesRead[:len(bytesRead)-1]), nil
}
}

// IF index > gr.Group.maxIndex, returns io.EOF
// CONTRACT: caller should hold gr.mtx
func (gr *GroupReader) openFile(index int) error {
Expand Down Expand Up @@ -725,20 +517,6 @@ func (gr *GroupReader) openFile(index int) error {
return nil
}

// PushLine makes the given line the current one, so the next time somebody
// calls ReadLine, this line will be returned.
// panics if called twice without calling ReadLine.
func (gr *GroupReader) PushLine(line string) {
gr.mtx.Lock()
defer gr.mtx.Unlock()

if gr.curLine == nil {
gr.curLine = []byte(line)
} else {
panic("PushLine failed, already have line")
}
}

// CurIndex returns cursor's file index.
func (gr *GroupReader) CurIndex() int {
gr.mtx.Lock()
Expand All @@ -753,32 +531,3 @@ func (gr *GroupReader) SetIndex(index int) error {
defer gr.mtx.Unlock()
return gr.openFile(index)
}

//--------------------------------------------------------------------------------

// A simple SearchFunc that assumes that the marker is of form
// <prefix><number>.
// For example, if prefix is '#HEIGHT:', the markers of expected to be of the form:
//
// #HEIGHT:1
// ...
// #HEIGHT:2
// ...
func MakeSimpleSearchFunc(prefix string, target int) SearchFunc {
return func(line string) (int, error) {
if !strings.HasPrefix(line, prefix) {
return -1, fmt.Errorf("Marker line did not have prefix: %v", prefix)
}
i, err := strconv.Atoi(line[len(prefix):])
if err != nil {
return -1, fmt.Errorf("Failed to parse marker line: %v", err.Error())
}
if target < i {
return 1, nil
} else if target == i {
return 0, nil
} else {
return -1, nil
}
}
}