[PATCH v17 14/17] Add GIT_DEBUG_REFS debugging mechanism
- From
Han-Wen Nienhuys via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Jun 16, 2020, 19:20 UTC
- Message-ID
- <88640ea13f92e9b24458d1de3188bf7233ba166d.1592335243.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.539.v17.git.1592335242.gitgitgadget@gmail.com>
From: Han-Wen Nienhuys <hanwen@google.com>
When set in the environment, GIT_DEBUG_REFS makes git print operations and results as they flow through the ref storage backend. This helps debug discrepancies between different ref backends.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> --- Makefile | 1 + refs.c | 3 + refs/debug.c | 358 ++++++++++++++++++++++++++++++++++++++++++ refs/refs-internal.h | 6 + t/t0033-debug-refs.sh | 18 +++ 5 files changed, 386 insertions(+) create mode 100644 refs/debug.c create mode 100755 t/t0033-debug-refs.sh
diff --git a/Makefile b/Makefile index feb2e52ad22..9c71bbdcbb8 100644 --- a/Makefile +++ b/Makefile @@ -961,6 +961,7 @@ LIB_OBJS += rebase.o LIB_OBJS += ref-filter.o LIB_OBJS += reflog-walk.o LIB_OBJS += refs.o +LIB_OBJS += refs/debug.o LIB_OBJS += refs/files-backend.o LIB_OBJS += refs/reftable-backend.o LIB_OBJS += refs/iterator.o diff --git a/refs.c b/refs.c index 4409080dfd8..bd1f3cc0e45 100644 --- a/refs.c +++ b/refs.c @@ -1750,6 +1750,9 @@ struct ref_store *get_main_ref_store(struct repository *r) r->ref_storage_format : DEFAULT_REF_STORAGE, REF_STORE_ALL_CAPS); + if (getenv("GIT_DEBUG_REFS")) { + r->refs_private = debug_wrap(r->refs_private); + } return r->refs_private; } diff --git a/refs/debug.c b/refs/debug.c new file mode 100644 index 00000000000..c33e684f5fc --- /dev/null +++ b/refs/debug.c @@ -0,0 +1,358 @@ + +#include "refs-internal.h" + +struct debug_ref_store { + struct ref_store base; + struct ref_store *refs; +}; + +extern struct ref_storage_be refs_be_debug; +struct ref_store *debug_wrap(struct ref_store *store); + +struct ref_store *debug_wrap(struct ref_store *store) +{ + struct debug_ref_store *res = malloc(sizeof(struct debug_ref_store)); + res->refs = store; + base_ref_store_init((struct ref_store *)res, &refs_be_debug); + return (struct ref_store *)res; +} + +static int debug_init_db(struct ref_store *refs, struct strbuf *err) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)refs; + int res = drefs->refs->be->init_db(drefs->refs, err); + return res; +} + +static int debug_transaction_prepare(struct ref_store *refs, + struct ref_transaction *transaction, + struct strbuf *err) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)refs; + int res; + transaction->ref_store = drefs->refs; + res = drefs->refs->be->transaction_prepare(drefs->refs, transaction, + err); + return res; +} + +static void print_update(int i, const char *refname, + const struct object_id *old_oid, + const struct object_id *new_oid, unsigned int flags, + unsigned int type, const char *msg) +{ + char o[200] = "null"; + char n[200] = "null"; + if (old_oid) + oid_to_hex_r(o, old_oid); + if (new_oid) + oid_to_hex_r(n, new_oid); + + type &= 0xf; /* see refs.h REF_* */ + flags &= REF_HAVE_NEW | REF_HAVE_OLD | REF_NO_DEREF | + REF_FORCE_CREATE_REFLOG | REF_LOG_ONLY; + printf("%d: %s %s -> %s (F=0x%x, T=0x%x) \"%s\"\n", i, refname, o, n, + flags, type, msg); +} + +static void print_transaction(struct ref_transaction *transaction) +{ + printf("transaction {\n"); + for (int i = 0; i < transaction->nr; i++) { + struct ref_update *u = transaction->updates[i]; + print_update(i, u->refname, &u->old_oid, &u->new_oid, u->flags, + u->type, u->msg); + } + printf("}\n"); +} + +static int debug_transaction_finish(struct ref_store *refs, + struct ref_transaction *transaction, + struct strbuf *err) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)refs; + int res; + transaction->ref_store = drefs->refs; + res = drefs->refs->be->transaction_finish(drefs->refs, transaction, + err); + print_transaction(transaction); + printf("finish: %d\n", res); + return res; +} + +static int debug_transaction_abort(struct ref_store *refs, + struct ref_transaction *transaction, + struct strbuf *err) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)refs; + int res; + transaction->ref_store = drefs->refs; + res = drefs->refs->be->transaction_abort(drefs->refs, transaction, err); + return res; +} + +static int debug_initial_transaction_commit(struct ref_store *refs, + struct ref_transaction *transaction, + struct strbuf *err) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)refs; + int res; + transaction->ref_store = drefs->refs; + res = drefs->refs->be->initial_transaction_commit(drefs->refs, + transaction, err); + return res; +} + +static int debug_pack_refs(struct ref_store *ref_store, unsigned int flags) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = drefs->refs->be->pack_refs(drefs->refs, flags); + return res; +} + +static int debug_create_symref(struct ref_store *ref_store, + const char *ref_name, const char *target, + const char *logmsg) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = drefs->refs->be->create_symref(drefs->refs, ref_name, target, + logmsg); + printf("create_symref: %s -> %s \"%s\": %d\n", ref_name, target, logmsg, + res); + return res; +} + +static int debug_delete_refs(struct ref_store *ref_store, const char *msg, + struct string_list *refnames, unsigned int flags) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = + drefs->refs->be->delete_refs(drefs->refs, msg, refnames, flags); + return res; +} + +static int debug_rename_ref(struct ref_store *ref_store, const char *oldref, + const char *newref, const char *logmsg) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = drefs->refs->be->rename_ref(drefs->refs, oldref, newref, + logmsg); + printf("rename_ref: %s -> %s \"%s\": %d\n", oldref, newref, logmsg, + res); + return res; +} + +static int debug_copy_ref(struct ref_store *ref_store, const char *oldref, + const char *newref, const char *logmsg) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = + drefs->refs->be->copy_ref(drefs->refs, oldref, newref, logmsg); + printf("copy_ref: %s -> %s \"%s\": %d\n", oldref, newref, logmsg, res); + return res; +} + +static int debug_write_pseudoref(struct ref_store *ref_store, + const char *pseudoref, + const struct object_id *oid, + const struct object_id *old_oid, + struct strbuf *err) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = drefs->refs->be->write_pseudoref(drefs->refs, pseudoref, oid, + old_oid, err); + char o[100] = "null"; + char n[100] = "null"; + if (oid) + oid_to_hex_r(o, oid); + if (old_oid) + oid_to_hex_r(n, old_oid); + printf("write_pseudoref: %s, %s => %s, err %s: %d\n", pseudoref, o, n, + err->buf, res); + return res; +} + +static int debug_delete_pseudoref(struct ref_store *ref_store, + const char *pseudoref, + const struct object_id *old_oid) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = drefs->refs->be->delete_pseudoref(drefs->refs, pseudoref, + old_oid); + char hex[100] = "null"; + if (old_oid) + oid_to_hex_r(hex, old_oid); + printf("delete_pseudoref: %s (%s): %d\n", pseudoref, hex, res); + return res; +} + +static struct ref_iterator * +debug_ref_iterator_begin(struct ref_store *ref_store, const char *prefix, + unsigned int flags) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + struct ref_iterator *res = + drefs->refs->be->iterator_begin(drefs->refs, prefix, flags); + return res; +} + +static int debug_read_raw_ref(struct ref_store *ref_store, const char *refname, + struct object_id *oid, struct strbuf *referent, + unsigned int *type) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = 0; + + oidcpy(oid, &null_oid); + res = drefs->refs->be->read_raw_ref(drefs->refs, refname, oid, referent, + type); + + if (res == 0) { + printf("read_raw_ref: %s: %s (=> %s) type %x: %d\n", refname, + oid_to_hex(oid), referent->buf, *type, res); + } else { + printf("read_raw_ref: %s err %d\n", refname, res); + } + return res; +} + +static struct ref_iterator * +debug_reflog_iterator_begin(struct ref_store *ref_store) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + struct ref_iterator *res = + drefs->refs->be->reflog_iterator_begin(drefs->refs); + printf("for_each_reflog_iterator_begin\n"); + return res; +} + +struct debug_reflog { + const char *refname; + each_reflog_ent_fn *fn; + void *cb_data; +}; + +static int debug_print_reflog_ent(struct object_id *old_oid, + struct object_id *new_oid, + const char *committer, timestamp_t timestamp, + int tz, const char *msg, void *cb_data) +{ + struct debug_reflog *dbg = (struct debug_reflog *)cb_data; + int ret; + char o[100] = "null"; + char n[100] = "null"; + if (old_oid) + oid_to_hex_r(o, old_oid); + if (new_oid) + oid_to_hex_r(n, new_oid); + + ret = dbg->fn(old_oid, new_oid, committer, timestamp, tz, msg, + dbg->cb_data); + printf("reflog_ent %s (ret %d): %s -> %s, %s %ld \"%s\"\n", + dbg->refname, ret, o, n, committer, (long int)timestamp, msg); + return ret; +} + +static int debug_for_each_reflog_ent(struct ref_store *ref_store, + const char *refname, each_reflog_ent_fn fn, + void *cb_data) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + struct debug_reflog dbg = { + .refname = refname, + .fn = fn, + .cb_data = cb_data, + }; + + int res = drefs->refs->be->for_each_reflog_ent( + drefs->refs, refname, &debug_print_reflog_ent, &dbg); + printf("for_each_reflog: %s: %d\n", refname, res); + return res; +} + +static int debug_for_each_reflog_ent_reverse(struct ref_store *ref_store, + const char *refname, + each_reflog_ent_fn fn, + void *cb_data) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + struct debug_reflog dbg = { + .refname = refname, + .fn = fn, + .cb_data = cb_data, + }; + int res = drefs->refs->be->for_each_reflog_ent_reverse( + drefs->refs, refname, &debug_print_reflog_ent, &dbg); + printf("for_each_reflog_reverse: %s: %d\n", refname, res); + return res; +} + +static int debug_reflog_exists(struct ref_store *ref_store, const char *refname) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = drefs->refs->be->reflog_exists(drefs->refs, refname); + printf("reflog_exists: %s: %d\n", refname, res); + return res; +} + +static int debug_create_reflog(struct ref_store *ref_store, const char *refname, + int force_create, struct strbuf *err) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = drefs->refs->be->create_reflog(drefs->refs, refname, + force_create, err); + return res; +} + +static int debug_delete_reflog(struct ref_store *ref_store, const char *refname) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = drefs->refs->be->delete_reflog(drefs->refs, refname); + return res; +} + +static int debug_reflog_expire(struct ref_store *ref_store, const char *refname, + const struct object_id *oid, unsigned int flags, + reflog_expiry_prepare_fn prepare_fn, + reflog_expiry_should_prune_fn should_prune_fn, + reflog_expiry_cleanup_fn cleanup_fn, + void *policy_cb_data) +{ + struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store; + int res = drefs->refs->be->reflog_expire(drefs->refs, refname, oid, + flags, prepare_fn, + should_prune_fn, cleanup_fn, + policy_cb_data); + return res; +} + +struct ref_storage_be refs_be_debug = { + NULL, + "debug", + NULL, + debug_init_db, + debug_transaction_prepare, + debug_transaction_finish, + debug_transaction_abort, + debug_initial_transaction_commit, + + debug_pack_refs, + debug_create_symref, + debug_delete_refs, + debug_rename_ref, + debug_copy_ref, + + debug_write_pseudoref, + debug_delete_pseudoref, + + debug_ref_iterator_begin, + debug_read_raw_ref, + + debug_reflog_iterator_begin, + debug_for_each_reflog_ent, + debug_for_each_reflog_ent_reverse, + debug_reflog_exists, + debug_create_reflog, + debug_delete_reflog, + debug_reflog_expire, +}; diff --git a/refs/refs-internal.h b/refs/refs-internal.h index 7afe4c28310..5417623c86e 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -713,4 +713,10 @@ struct ref_store { void base_ref_store_init(struct ref_store *refs, const struct ref_storage_be *be); +/* + * Print out ref operations as they occur. Useful for debugging alternate ref + * backends. + */ +struct ref_store *debug_wrap(struct ref_store *store); + #endif /* REFS_REFS_INTERNAL_H */ diff --git a/t/t0033-debug-refs.sh b/t/t0033-debug-refs.sh new file mode 100755 index 00000000000..ed76c2c84a1 --- /dev/null +++ b/t/t0033-debug-refs.sh @@ -0,0 +1,18 @@ +#!/bin/sh +# +# Copyright (c) 2020 Google LLC +# + +test_description='cross-check reftable with files, using GIT_DEBUG_REFS output' + +. ./test-lib.sh + +test_expect_success 'GIT_DEBUG_REFS' ' + git init --ref-storage=files files && + git init --ref-storage=reftable reftable && + (cd files && GIT_DEBUG_REFS=1 test_commit message file) > files.txt && + (cd reftable && GIT_DEBUG_REFS=1 test_commit message file) > reftable.txt && + test_cmp files.txt reftable.txt +' + +test_done
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