jared
f7035049e7
Minimal skeleton for uscogdata v0.1. Internal session layer with lazy cog_open(), manifest fetch+validate+cache, view registration placeholder. Depends on DuckDB >=1.0, httr2, jsonlite. inst/schemas/provenance-v1.json ships the structured provenance JSON Schema.
44 lines
1.1 KiB
R
44 lines
1.1 KiB
R
# R/session.R
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#' Internal: open session, register views, cache manifest.
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#' Not exported. Called lazily by verbs via .ensure_session().
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#' @noRd
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cog_open <- function(url = .resolve_url(),
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cache_dir = .resolve_cache_dir()) {
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if (!dir.exists(cache_dir)) dir.create(cache_dir, recursive = TRUE)
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con <- DBI::dbConnect(duckdb::duckdb())
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DBI::dbExecute(con, "INSTALL httpfs; LOAD httpfs;")
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manifest <- .fetch_or_cache_manifest(url, cache_dir)
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.validate_schema(manifest, expected_version = 2L)
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.validate_scope(manifest)
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.register_views(con, url, manifest)
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.uscogdata_env$con <- con
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.uscogdata_env$manifest <- manifest
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.uscogdata_env$url <- url
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.uscogdata_env$cache_dir <- cache_dir
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invisible(con)
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}
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#' @noRd
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.ensure_session <- function() {
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if (is.null(.uscogdata_env$con) ||
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!DBI::dbIsValid(.uscogdata_env$con)) {
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cog_open()
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}
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.uscogdata_env$con
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}
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#' @noRd
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cog_close <- function() {
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if (!is.null(.uscogdata_env$con) && DBI::dbIsValid(.uscogdata_env$con)) {
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DBI::dbDisconnect(.uscogdata_env$con, shutdown = TRUE)
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}
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.uscogdata_env$con <- NULL
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.uscogdata_env$manifest <- NULL
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}
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