migrator

Documentation

Overview

Package migrator is responsible for planning and executing cypher migrations.

Index

• type Batch
• type Builder
• type DatabaseGraphVersion
• type DatabaseModel
  • func (dbm DatabaseModel) ContainsHigherVersion(folder string, version *semver.Version) bool
  • func (dbm DatabaseModel) GetFileTimestamps(folder string, version *semver.Version) map[int64]bool
  • func (dbm DatabaseModel) HasAnyVersion() bool
  • func (dbm DatabaseModel) MarshalJSON() ([]byte, error)
  • func (dbm DatabaseModel) String() string
• type ExecutionStep
  • func (s ExecutionStep) Command() []string
  • func (s ExecutionStep) Cypher() *bytes.Buffer
  • func (s ExecutionStep) IsCypher() bool
• type ExecutionSteps
  • func (e *ExecutionSteps) AddCommand(args []string)
  • func (e *ExecutionSteps) AddCypher(cypher ...string)
  • func (e ExecutionSteps) IsEmpty() bool
  • func (e ExecutionSteps) String() string
• type FileType
• type LocalFolders
  • func (lc LocalFolders) SortByVersion()
• type LocalVersionFolder
• type MigrationFile
• type MigrationScripts
  • func (ms *MigrationScripts) Add(in *MigrationScripts)
  • func (ms *MigrationScripts) ContainsMigrations() bool
  • func (ms *MigrationScripts) SortDownFiles()
  • func (ms *MigrationScripts) SortUpFiles()
• type Neo4jSession
• type Planner
  • func NewPlanner(cfg *config.Config) (*Planner, error)
  • func (p *Planner) CreateBuilder(steps *ExecutionSteps, abs bool) Builder
  • func (p *Planner) NewScanner(root string) (*Scanner, error)
  • func (p *Planner) Plan(localFolders LocalFolders, dbModel DatabaseModel, targetVersion *TargetVersion, ...) error
  • func (p *Planner) Version(ctx context.Context, session neo4j.SessionWithContext) (DatabaseModel, error)
• type Scanner
  • func (s *Scanner) GenerateMigrationFiles(folderName string, version *TargetVersion, migrationName string, ...) ([]string, error)
  • func (s *Scanner) ScanFolders() (LocalFolders, error)
• type TargetVersion
  • func ParseTargetVersion(v string) (*TargetVersion, error)
  • func (a *TargetVersion) Set(v string) error
  • func (a *TargetVersion) String() string
  • func (*TargetVersion) Type() string

Types

type Batch

type Batch string

type Builder

type Builder func(cf *MigrationFile, version *semver.Version) error

type DatabaseGraphVersion

type DatabaseGraphVersion struct {
	Version        *semver.Version
	FileTimestamps map[int64]bool
}

DatabaseGraphVersion holds all executed files per version.

type DatabaseModel

type DatabaseModel map[string][]DatabaseGraphVersion

DatabaseModel holds database version of all migrations of all folders. Key is folder name and value contains all applied versions with all executed files.

func (DatabaseModel) ContainsHigherVersion

func (dbm DatabaseModel) ContainsHigherVersion(folder string, version *semver.Version) bool

ContainsHigherVersion check if there is folder with higher version than specified.

func (DatabaseModel) GetFileTimestamps

func (dbm DatabaseModel) GetFileTimestamps(folder string, version *semver.Version) map[int64]bool

GetFileTimestamps returns all executed files from DB.

func (DatabaseModel) HasAnyVersion

func (dbm DatabaseModel) HasAnyVersion() bool

HasAnyVersion checks if there is any version stored in DB.

func (DatabaseModel) MarshalJSON

func (dbm DatabaseModel) MarshalJSON() ([]byte, error)

MarshalJSON returns the JSON encoding of DatabaseModel.

func (DatabaseModel) String

func (dbm DatabaseModel) String() string

String converts DatabaseModel into JSON which is shrink.

type ExecutionStep

type ExecutionStep struct {
	// contains filtered or unexported fields
}

func (ExecutionStep) Command

func (s ExecutionStep) Command() []string

Command returns current command with all parameters.

func (ExecutionStep) Cypher

func (s ExecutionStep) Cypher() *bytes.Buffer

Cypher returns buffer with all cyphers in current step.

func (ExecutionStep) IsCypher

func (s ExecutionStep) IsCypher() bool

IsCypher returns true if current step is Cypher. But does not check if cypher really contains something. So returns true for empty Cypher too.

type ExecutionSteps

type ExecutionSteps []ExecutionStep

func (*ExecutionSteps) AddCommand

func (e *ExecutionSteps) AddCommand(args []string)

AddCommand adds command with parameters to step list.

func (*ExecutionSteps) AddCypher

func (e *ExecutionSteps) AddCypher(cypher ...string)

AddCypher adds all Cyphers into one buffer. If current step is Cypher as well, it is reused. Otherwise new buffer is created.

func (ExecutionSteps) IsEmpty

func (e ExecutionSteps) IsEmpty() bool

IsEmpty checks if there are steps to do.

func (ExecutionSteps) String

func (e ExecutionSteps) String() string

String converts all cyphers and command calls into single long string. Is not really suitable for Cypher shell, but can be used for debug print.

type FileType

type FileType int

const (
	Cypher FileType = iota
	Command
)

type LocalFolders

type LocalFolders []*LocalVersionFolder

LocalFolders handles all migration files for all versions across all folders.

func (LocalFolders) SortByVersion

func (lc LocalFolders) SortByVersion()

SortByVersion all folders in ascending order.

type LocalVersionFolder

type LocalVersionFolder struct {
	Version *semver.Version
	// SchemaFolder contains all up/down files of base schema folder.
	SchemaFolder *MigrationScripts
	// ExtraFolders contains all up/down files per folder, which name is key of the map.
	ExtraFolders map[string]*MigrationScripts
	// Snapshots contains all snapshot files for given version per batch, which name is key of the map.
	Snapshots map[Batch]*MigrationFile
}

LocalVersionFolder handles all migration files for single version across all folders.

type MigrationFile

type MigrationFile struct {
	FolderName  string
	Path        string
	FileType    FileType
	Timestamp   int64
	IsDowngrade bool
	IsSnapshot  bool
}

MigrationFile specify all details about single file to run during migration.

type MigrationScripts

type MigrationScripts struct {
	Up   []*MigrationFile
	Down []*MigrationFile
}

MigrationScripts handles all up and potentially down files. If folder is 'change' type, only up files are used as this is only applied during up action.

func (*MigrationScripts) Add

func (ms *MigrationScripts) Add(in *MigrationScripts)

Add merge migrations scripts with in scripts.

func (*MigrationScripts) ContainsMigrations

func (ms *MigrationScripts) ContainsMigrations() bool

ContainsMigrations verify if there is at least some up or down migration.

func (*MigrationScripts) SortDownFiles

func (ms *MigrationScripts) SortDownFiles()

SortDownFiles in descending order.

func (*MigrationScripts) SortUpFiles

func (ms *MigrationScripts) SortUpFiles()

SortUpFiles in ascending order.

type Neo4jSession

type Neo4jSession struct {
	neo4j.SessionWithContext
}

type Planner

type Planner struct {
	// contains filtered or unexported fields
}

func NewPlanner

func NewPlanner(cfg *config.Config) (*Planner, error)

NewPlanner creates Planner instance and returns error if provided config is not valid.

func (*Planner) CreateBuilder

func (p *Planner) CreateBuilder(steps *ExecutionSteps, abs bool) Builder

CreateBuilder creates default Cypher builder.

func (*Planner) NewScanner

func (p *Planner) NewScanner(root string) (*Scanner, error)

NewScanner creates file scanner.

func (*Planner) Plan

func (p *Planner) Plan(
	localFolders LocalFolders,
	dbModel DatabaseModel,
	targetVersion *TargetVersion,
	batch Batch,
	builder Builder,
) error

Plan prepares execution plan with given builder.

func (*Planner) Version

func (p *Planner) Version(ctx context.Context, session neo4j.SessionWithContext) (DatabaseModel, error)

Version retrieves version of current state of DB.

type Scanner

type Scanner struct {
	// contains filtered or unexported fields
}

func (*Scanner) GenerateMigrationFiles

func (s *Scanner) GenerateMigrationFiles(
	folderName string,
	version *TargetVersion,
	migrationName string,
	upType, downType FileType,
) ([]string, error)

GenerateMigrationFiles creates empty files based on config and passed arguments.

func (*Scanner) ScanFolders

func (s *Scanner) ScanFolders() (LocalFolders, error)

ScanFolders start scanning and returns all up and down files divided per version and revision. Result is not sorted by default, use SortByVersion() to sort it by semver version.

type TargetVersion

type TargetVersion struct {
	Version  *semver.Version `json:"version,omitempty"`
	Revision int64           `json:"rev,omitempty"`
}

TargetVersion holds version of a graph.

func ParseTargetVersion

func ParseTargetVersion(v string) (*TargetVersion, error)

ParseTargetVersion parse string as semver version with revision.

func (*TargetVersion) Set

func (a *TargetVersion) Set(v string) error

Set sets version from string. Can be used with flag package.

func (*TargetVersion) String

func (a *TargetVersion) String() string

func (*TargetVersion) Type

func (*TargetVersion) Type() string

Type returns type name, so it can be used with flag package.