bundle-uri: parse bundle.heuristic=creationToken
The bundle.heuristic value communicates that the bundle list is organized to make use of the bundle.<id>.creationToken values that may be provided in the bundle list. Those values will create a total order on the bundles, allowing the Git client to download them in a specific order and even remember previously-downloaded bundles by storing the maximum creation token value. Before implementing any logic that parses or uses the bundle.<id>.creationToken values, teach Git to parse the bundle.heuristic value from a bundle list. We can use 'test-tool bundle-uri' to print the heuristic value and verify that the parsing works correctly. As an extra precaution, create the internal 'heuristics' array to be a list of (enum, string) pairs so we can iterate through the array entries carefully, regardless of the enum values. Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee committed
Jan 31, 2023 at 13:29 UTC
c93c3d2fa42bec64948441cb339d78e2044ff9a3
4 files changed
+74
Documentation/config/bundle.txt
+7
index daa21eb674..3faae38685 100644
--- a/Documentation/config/bundle.txt
+++ b/Documentation/config/bundle.txt
@@ -15,6 +15,13 @@ bundle.mode::
complete understanding of the bundled information (`all`) or if any one
of the listed bundle URIs is sufficient (`any`).
+bundle.heuristic::
+ If this string-valued key exists, then the bundle list is designed to
+ work well with incremental `git fetch` commands. The heuristic signals
+ that there are additional keys available for each bundle that help
+ determine which subset of bundles the client should download. The
+ only value currently understood is `creationToken`.
+
bundle.<id>.*::
The `bundle.<id>.*` keys are used to describe a single item in the
bundle list, grouped under `<id>` for identification purposes.
bundle-uri.c
+34
index 36268dda17..36ec542718 100644
--- a/bundle-uri.c
+++ b/bundle-uri.c
@@ -9,6 +9,14 @@
#include "config.h"
#include "remote.h"
+static struct {
+ enum bundle_list_heuristic heuristic;
+ const char *name;
+} heuristics[BUNDLE_HEURISTIC__COUNT] = {
+ { BUNDLE_HEURISTIC_NONE, ""},
+ { BUNDLE_HEURISTIC_CREATIONTOKEN, "creationToken" },
+};
+
static int compare_bundles(const void *hashmap_cmp_fn_data,
const struct hashmap_entry *he1,
const struct hashmap_entry *he2,
@@ -100,6 +108,17 @@ void print_bundle_list(FILE *fp, struct bundle_list *list)
fprintf(fp, "\tversion = %d\n", list->version);
fprintf(fp, "\tmode = %s\n", mode);
+ if (list->heuristic) {
+ int i;
+ for (i = 0; i < BUNDLE_HEURISTIC__COUNT; i++) {
+ if (heuristics[i].heuristic == list->heuristic) {
+ printf("\theuristic = %s\n",
+ heuristics[list->heuristic].name);
+ break;
+ }
+ }
+ }
+
for_all_bundles_in_list(list, summarize_bundle, fp);
}
@@ -142,6 +161,21 @@ static int bundle_list_update(const char *key, const char *value,
return 0;
}
+ if (!strcmp(subkey, "heuristic")) {
+ int i;
+ for (i = 0; i < BUNDLE_HEURISTIC__COUNT; i++) {
+ if (heuristics[i].heuristic &&
+ heuristics[i].name &&
+ !strcmp(value, heuristics[i].name)) {
+ list->heuristic = heuristics[i].heuristic;
+ return 0;
+ }
+ }
+
+ /* Ignore unknown heuristics. */
+ return 0;
+ }
+
/* Ignore other unknown global keys. */
return 0;
}
bundle-uri.h
+14
index d5e89f1671..2e44a50a90 100644
--- a/bundle-uri.h
+++ b/bundle-uri.h
@@ -52,6 +52,14 @@ enum bundle_list_mode {
BUNDLE_MODE_ANY
};
+enum bundle_list_heuristic {
+ BUNDLE_HEURISTIC_NONE = 0,
+ BUNDLE_HEURISTIC_CREATIONTOKEN,
+
+ /* Must be last. */
+ BUNDLE_HEURISTIC__COUNT
+};
+
/**
* A bundle_list contains an unordered set of remote_bundle_info structs,
* as well as information about the bundle listing, such as version and
@@ -75,6 +83,12 @@ struct bundle_list {
* advertised by the bundle list at that location.
*/
char *baseURI;
+
+ /**
+ * A list can have a heuristic, which helps reduce the number of
+ * downloaded bundles.
+ */
+ enum bundle_list_heuristic heuristic;
};
void init_bundle_list(struct bundle_list *list);
t/t5750-bundle-uri-parse.sh
+19
index 7b4f930e53..6fc92a9c0d 100755
--- a/t/t5750-bundle-uri-parse.sh
+++ b/t/t5750-bundle-uri-parse.sh
@@ -250,4 +250,23 @@ test_expect_success 'parse config format edge cases: empty key or value' '
test_cmp_config_output expect actual
'
+test_expect_success 'parse config format: creationToken heuristic' '
+ cat >expect <<-\EOF &&
+ [bundle]
+ version = 1
+ mode = all
+ heuristic = creationToken
+ [bundle "one"]
+ uri = http://example.com/bundle.bdl
+ [bundle "two"]
+ uri = https://example.com/bundle.bdl
+ [bundle "three"]
+ uri = file:///usr/share/git/bundle.bdl
+ EOF
+
+ test-tool bundle-uri parse-config expect >actual 2>err &&
+ test_must_be_empty err &&
+ test_cmp_config_output expect actual
+'
+
test_done