sru

Documentation

Overview

Package sru implements a minimal SRU (Search/Retrieve via URL) 1.2 server. Supports operations: explain, searchRetrieve. CQL support is minimal: free-text terms and index=value queries.

Index

• Constants
• func Handler(cfg ServerConfig) http.Handler
• type Index
• type Schema
• type SearchFunc
• type SearchResult
• type ServerConfig

Constants

const (
	Version        = "1.2"
	NS             = "http://www.loc.gov/zing/srw/"
	DiagNS         = "http://www.loc.gov/zing/srw/diagnostic/"
	DefaultMaxRecs = 100

	// Standard record schema identifiers.
	SchemaDC      = "info:srw/schema/1/dc-v1.1"
	SchemaMARCXML = "info:srw/schema/1/marcxml-v1.1"
	SchemaMODS    = "info:srw/schema/1/mods-v3.6"
)

const (
	DiagGeneralSystemError        = "info:srw/diagnostic/1/1"
	DiagUnsupportedOperation      = "info:srw/diagnostic/1/4"
	DiagUnsupportedVersion        = "info:srw/diagnostic/1/5"
	DiagQuerySyntaxError          = "info:srw/diagnostic/1/10"
	DiagUnsupportedIndex          = "info:srw/diagnostic/1/16"
	DiagUnknownSchemaForRetrieval = "info:srw/diagnostic/1/66"
)

Standard SRU diagnostic URIs.

Functions

func Handler

func Handler(cfg ServerConfig) http.Handler

Handler returns an http.Handler that implements the SRU protocol.

Types

type Index

type Index struct {
	CQLName string
	Title   string
	Field   string // internal field name for filtering; empty = free text query
}

Index maps a CQL index name to an internal field name.

type Schema

type Schema struct {
	Name       string // short name, e.g. "oai_dc"
	Identifier string // URI, e.g. "info:srw/schema/1/dc-v1.1"
	Title      string
}

Schema describes a supported record schema.

type SearchFunc

type SearchFunc func(ctx context.Context, index, value string, offset, size int) (*SearchResult, error)

SearchFunc is the callback the app provides. It receives the parsed CQL query and pagination params, and returns encoded records. The index and value come from CQL parsing. Index is empty for free-text (serverChoice). Offset is 0-based. Size is the maximum number of records to return.

type SearchResult

type SearchResult struct {
	Total   int
	Records [][]byte // each entry is an encoded record (e.g. OAI-DC XML)
}

SearchResult is what the search callback returns to the SRU handler.

type ServerConfig

type ServerConfig struct {
	Database string   // database name for explain
	Title    string   // human-readable title for explain
	Indexes  []Index  // supported CQL indexes
	Schemas  []Schema // supported record schemas
	Search   SearchFunc
}

ServerConfig configures an SRU endpoint.