go-vise

Constrained Size Output Virtual Machine
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default.go (2425B)

      1 package engine
      2 
      3 import (
      4 	"context"
      5 	"fmt"
      6 	"os"
      7 	"path"
      8 
      9 	"git.defalsify.org/vise.git/cache"
     10 	"git.defalsify.org/vise.git/persist"
     11 	"git.defalsify.org/vise.git/resource"
     12 	"git.defalsify.org/vise.git/state"
     13 )
     14 
     15 // NewDefaultEngine is a convenience function to instantiate a filesystem-backed engine with no output constraints.
     16 func NewDefaultEngine(dir string, persisted bool, session *string) (EngineIsh, error) {
     17 	var err error
     18 	st := state.NewState(0)
     19 	rs := resource.NewFsResource(dir)
     20 	ca := cache.NewCache()
     21 	cfg := Config{
     22 		Root: "root",
     23 	}
     24 	if session != nil {
     25 		cfg.SessionId = *session
     26 	} else if !persisted {
     27 		return nil, fmt.Errorf("session must be set if persist is used")	
     28 	}
     29 	ctx := context.TODO()
     30 	var en EngineIsh
     31 	if persisted {
     32 		dp := path.Join(dir, ".state")
     33 		err = os.MkdirAll(dp, 0700)
     34 		if err != nil {
     35 			return nil, err
     36 		}
     37 		pr := persist.NewFsPersister(dp)
     38 		en, err = NewPersistedEngine(ctx, cfg, pr, rs)
     39 		if err != nil {
     40 			Logg.Infof("persisted engine create error. trying again with persisting empty state first...")
     41 			pr = pr.WithContent(&st, ca)
     42 			err = pr.Save(cfg.SessionId)
     43 			if err != nil {
     44 				return nil, err
     45 			}
     46 			en, err = NewPersistedEngine(ctx, cfg, pr, rs)
     47 		}
     48 	} else {
     49 		enb := NewEngine(ctx, cfg, &st, rs, ca)
     50 		en = &enb
     51 	}
     52 	return en, err
     53 }
     54 
     55 // NewSizedEngine is a convenience function to instantiate a filesystem-backed engine with a specified output constraint.
     56 func NewSizedEngine(dir string, size uint32, persisted bool, session *string) (EngineIsh, error) {
     57 	var err error
     58 	st := state.NewState(0)
     59 	rs := resource.NewFsResource(dir)
     60 	ca := cache.NewCache()
     61 	cfg := Config{
     62 		OutputSize: size,
     63 		Root: "root",
     64 	}
     65 	if session != nil {
     66 		cfg.SessionId = *session
     67 	} else if !persisted {
     68 		return nil, fmt.Errorf("session must be set if persist is used")
     69 	}
     70 	ctx := context.TODO()
     71 	var en EngineIsh
     72 	if persisted {
     73 		dp := path.Join(dir, ".state")
     74 		err = os.MkdirAll(dp, 0700)
     75 		if err != nil {
     76 			return nil, err
     77 		}
     78 		pr := persist.NewFsPersister(dp)
     79 		en, err = NewPersistedEngine(ctx, cfg, pr, rs)
     80 		if err != nil {
     81 			Logg.Infof("persisted engine create error. trying again with persisting empty state first...")
     82 			pr = pr.WithContent(&st, ca)
     83 			err = pr.Save(cfg.SessionId)
     84 			if err != nil {
     85 				return nil, err
     86 			}
     87 			en, err = NewPersistedEngine(ctx, cfg, pr, rs)
     88 		}
     89 	} else {
     90 		enb := NewEngine(ctx, cfg, &st, rs, ca)
     91 		en = &enb
     92 	}
     93 	return en, err
     94 }