chore(tvix): move store golang bindings to tvix/store-go
Similar to the castore-go CL before, this also updates the store-go bindings to the new layout. Change-Id: Id73d7ad43f7d70171ab021728e303300c5db71f0 Reviewed-on: https://cl.tvl.fyi/c/depot/+/9788 Tested-by: BuildkiteCI Reviewed-by: Connor Brewster <cbrewster@hey.com>
This commit is contained in:
Florian Klink
flokli
parent
e38733a955
commit
1b26bf21e3
20 changed files with 95 additions and 10 deletions
273
tvix/store-go/export.go
Normal file
273
tvix/store-go/export.go
Normal file
|
|
@ -0,0 +1,273 @@
|
|||
package storev1
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"io"
|
||||
"path"
|
||||
|
||||
castorev1pb "code.tvl.fyi/tvix/castore/protos"
|
||||
"github.com/nix-community/go-nix/pkg/nar"
|
||||
)
|
||||
|
||||
type DirectoryLookupFn func([]byte) (*castorev1pb.Directory, error)
|
||||
type BlobLookupFn func([]byte) (io.ReadCloser, error)
|
||||
|
||||
// Export will traverse a given root node, and write the contents in NAR format
|
||||
// to the passed Writer.
|
||||
// It uses directoryLookupFn and blobLookupFn to resolve references.
|
||||
func Export(
|
||||
w io.Writer,
|
||||
rootNode *castorev1pb.Node,
|
||||
directoryLookupFn DirectoryLookupFn,
|
||||
blobLookupFn BlobLookupFn,
|
||||
) error {
|
||||
// initialize a NAR writer
|
||||
narWriter, err := nar.NewWriter(w)
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to initialize nar writer: %w", err)
|
||||
}
|
||||
defer narWriter.Close()
|
||||
|
||||
// populate rootHeader
|
||||
rootHeader := &nar.Header{
|
||||
Path: "/",
|
||||
}
|
||||
|
||||
// populate a stack
|
||||
// we will push paths and directories to it when entering a directory,
|
||||
// and emit individual elements to the NAR writer, draining the Directory object.
|
||||
// once it's empty, we can pop it off the stack.
|
||||
var stackPaths = []string{}
|
||||
var stackDirectories = []*castorev1pb.Directory{}
|
||||
|
||||
// peek at the pathInfo root and assemble the root node and write to writer
|
||||
// in the case of a regular file, we retrieve and write the contents, close and exit
|
||||
// in the case of a symlink, we write the symlink, close and exit
|
||||
if fileNode := rootNode.GetFile(); fileNode != nil {
|
||||
rootHeader.Type = nar.TypeRegular
|
||||
rootHeader.Size = int64(fileNode.GetSize())
|
||||
rootHeader.Executable = fileNode.GetExecutable()
|
||||
err := narWriter.WriteHeader(rootHeader)
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to write root header: %w", err)
|
||||
}
|
||||
|
||||
// if it's a regular file, retrieve and write the contents
|
||||
blobReader, err := blobLookupFn(fileNode.GetDigest())
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to lookup blob: %w", err)
|
||||
}
|
||||
defer blobReader.Close()
|
||||
|
||||
_, err = io.Copy(narWriter, blobReader)
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to read from blobReader: %w", err)
|
||||
}
|
||||
|
||||
err = blobReader.Close()
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to close content reader: %w", err)
|
||||
}
|
||||
|
||||
err = narWriter.Close()
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to close nar reader: %w", err)
|
||||
}
|
||||
|
||||
return nil
|
||||
} else if symlinkNode := rootNode.GetSymlink(); symlinkNode != nil {
|
||||
rootHeader.Type = nar.TypeSymlink
|
||||
rootHeader.LinkTarget = string(symlinkNode.GetTarget())
|
||||
err := narWriter.WriteHeader(rootHeader)
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to write root header: %w", err)
|
||||
}
|
||||
|
||||
err = narWriter.Close()
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to close nar reader: %w", err)
|
||||
}
|
||||
} else if directoryNode := rootNode.GetDirectory(); directoryNode != nil {
|
||||
// We have a directory at the root, look it up and put in on the stack.
|
||||
directory, err := directoryLookupFn(directoryNode.GetDigest())
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to lookup directory: %w", err)
|
||||
}
|
||||
stackDirectories = append(stackDirectories, directory)
|
||||
stackPaths = append(stackPaths, "/")
|
||||
|
||||
err = narWriter.WriteHeader(&nar.Header{
|
||||
Path: "/",
|
||||
Type: nar.TypeDirectory,
|
||||
})
|
||||
|
||||
if err != nil {
|
||||
return fmt.Errorf("error writing header: %w", err)
|
||||
}
|
||||
} else {
|
||||
panic("invalid type") // unreachable
|
||||
}
|
||||
|
||||
// as long as the stack is not empty, we keep running.
|
||||
for {
|
||||
if len(stackDirectories) == 0 {
|
||||
return nil
|
||||
}
|
||||
|
||||
// Peek at the current top of the stack.
|
||||
topOfStack := stackDirectories[len(stackDirectories)-1]
|
||||
topOfStackPath := stackPaths[len(stackPaths)-1]
|
||||
|
||||
// get the next element that's lexicographically smallest, and drain it from
|
||||
// the current directory on top of the stack.
|
||||
nextNode := drainNextNode(topOfStack)
|
||||
|
||||
// If nextNode returns nil, there's nothing left in the directory node, so we
|
||||
// can emit it from the stack.
|
||||
// Contrary to the import case, we don't emit the node popping from the stack, but when pushing.
|
||||
if nextNode == nil {
|
||||
// pop off stack
|
||||
stackDirectories = stackDirectories[:len(stackDirectories)-1]
|
||||
stackPaths = stackPaths[:len(stackPaths)-1]
|
||||
|
||||
continue
|
||||
}
|
||||
|
||||
switch n := (nextNode).(type) {
|
||||
case *castorev1pb.DirectoryNode:
|
||||
err := narWriter.WriteHeader(&nar.Header{
|
||||
Path: path.Join(topOfStackPath, string(n.GetName())),
|
||||
Type: nar.TypeDirectory,
|
||||
})
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to write nar header: %w", err)
|
||||
}
|
||||
|
||||
d, err := directoryLookupFn(n.GetDigest())
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to lookup directory: %w", err)
|
||||
}
|
||||
|
||||
// add to stack
|
||||
stackDirectories = append(stackDirectories, d)
|
||||
stackPaths = append(stackPaths, path.Join(topOfStackPath, string(n.GetName())))
|
||||
case *castorev1pb.FileNode:
|
||||
err := narWriter.WriteHeader(&nar.Header{
|
||||
Path: path.Join(topOfStackPath, string(n.GetName())),
|
||||
Type: nar.TypeRegular,
|
||||
Size: int64(n.GetSize()),
|
||||
Executable: n.GetExecutable(),
|
||||
})
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to write nar header: %w", err)
|
||||
}
|
||||
|
||||
// copy file contents
|
||||
contentReader, err := blobLookupFn(n.GetDigest())
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to get blob: %w", err)
|
||||
}
|
||||
defer contentReader.Close()
|
||||
|
||||
_, err = io.Copy(narWriter, contentReader)
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to copy contents from contentReader: %w", err)
|
||||
}
|
||||
|
||||
err = contentReader.Close()
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to close content reader: %w", err)
|
||||
}
|
||||
case *castorev1pb.SymlinkNode:
|
||||
err := narWriter.WriteHeader(&nar.Header{
|
||||
Path: path.Join(topOfStackPath, string(n.GetName())),
|
||||
Type: nar.TypeSymlink,
|
||||
LinkTarget: string(n.GetTarget()),
|
||||
})
|
||||
if err != nil {
|
||||
return fmt.Errorf("unable to write nar header: %w", err)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// drainNextNode will drain a directory message with one of its child nodes,
|
||||
// whichever comes first alphabetically.
|
||||
func drainNextNode(d *castorev1pb.Directory) interface{} {
|
||||
switch v := (smallestNode(d)).(type) {
|
||||
case *castorev1pb.DirectoryNode:
|
||||
d.Directories = d.Directories[1:]
|
||||
return v
|
||||
case *castorev1pb.FileNode:
|
||||
d.Files = d.Files[1:]
|
||||
return v
|
||||
case *castorev1pb.SymlinkNode:
|
||||
d.Symlinks = d.Symlinks[1:]
|
||||
return v
|
||||
case nil:
|
||||
return nil
|
||||
default:
|
||||
panic("invalid type encountered")
|
||||
}
|
||||
}
|
||||
|
||||
// smallestNode will return the node from a directory message,
|
||||
// whichever comes first alphabetically.
|
||||
func smallestNode(d *castorev1pb.Directory) interface{} {
|
||||
childDirectories := d.GetDirectories()
|
||||
childFiles := d.GetFiles()
|
||||
childSymlinks := d.GetSymlinks()
|
||||
|
||||
if len(childDirectories) > 0 {
|
||||
if len(childFiles) > 0 {
|
||||
if len(childSymlinks) > 0 {
|
||||
// directories,files,symlinks
|
||||
return smallerNode(smallerNode(childDirectories[0], childFiles[0]), childSymlinks[0])
|
||||
} else {
|
||||
// directories,files,!symlinks
|
||||
return smallerNode(childDirectories[0], childFiles[0])
|
||||
}
|
||||
} else {
|
||||
// directories,!files
|
||||
if len(childSymlinks) > 0 {
|
||||
// directories,!files,symlinks
|
||||
return smallerNode(childDirectories[0], childSymlinks[0])
|
||||
} else {
|
||||
// directories,!files,!symlinks
|
||||
return childDirectories[0]
|
||||
}
|
||||
}
|
||||
} else {
|
||||
// !directories
|
||||
if len(childFiles) > 0 {
|
||||
// !directories,files
|
||||
if len(childSymlinks) > 0 {
|
||||
// !directories,files,symlinks
|
||||
return smallerNode(childFiles[0], childSymlinks[0])
|
||||
} else {
|
||||
// !directories,files,!symlinks
|
||||
return childFiles[0]
|
||||
}
|
||||
} else {
|
||||
//!directories,!files
|
||||
if len(childSymlinks) > 0 {
|
||||
//!directories,!files,symlinks
|
||||
return childSymlinks[0]
|
||||
} else {
|
||||
//!directories,!files,!symlinks
|
||||
return nil
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// smallerNode compares two nodes by their name,
|
||||
// and returns the one with the smaller name.
|
||||
// both nodes may not be nil, we do check for these cases in smallestNode.
|
||||
func smallerNode(a interface{ GetName() []byte }, b interface{ GetName() []byte }) interface{ GetName() []byte } {
|
||||
if string(a.GetName()) < string(b.GetName()) {
|
||||
return a
|
||||
} else {
|
||||
return b
|
||||
}
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue