[PATCH 1/4] fsmonitor: change last update timestamp on the index_state to opaque token
- From
- Kevin Willford via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Jan 7, 2020, 19:04 UTC
- Message-ID
- <679bf4e0dd16f7d6f4ba1f05af50cca24b5abee4.1578423871.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.510.git.1578423871.gitgitgadget@gmail.com>
From: Kevin Willford <Kevin.Willford@microsoft.com>
Some file system monitors might not use or take a timestamp for processing and in the case of watchman could have race conditions with using a timestamp. Watchman uses something called a clockid that is used for race free queries to it. The clockid for watchman is simply a string.
Change the fsmonitor_last_update from being a uint64_t to a char pointer so that any arbitrary data can be stored in it and passed back to the fsmonitor.
Signed-off-by: Kevin Willford <Kevin.Willford@microsoft.com> --- cache.h | 2 +- fsmonitor.c | 49 ++++++++++++++++++++++------------ t/helper/test-dump-fsmonitor.c | 2 +- 3 files changed, 34 insertions(+), 19 deletions(-)
diff --git a/cache.h b/cache.h index 1554488d66..170c125db3 100644 --- a/cache.h +++ b/cache.h @@ -324,7 +324,7 @@ struct index_state { struct hashmap dir_hash; struct object_id oid; struct untracked_cache *untracked; - uint64_t fsmonitor_last_update; + char *fsmonitor_last_update; struct ewah_bitmap *fsmonitor_dirty; struct mem_pool *ce_mem_pool; struct progress *progress; diff --git a/fsmonitor.c b/fsmonitor.c index 868cca01e2..9860587225 100644 --- a/fsmonitor.c +++ b/fsmonitor.c @@ -6,8 +6,9 @@ #include "run-command.h" #include "strbuf.h" -#define INDEX_EXTENSION_VERSION (1) -#define HOOK_INTERFACE_VERSION (1) +#define INDEX_EXTENSION_VERSION1 (1) +#define INDEX_EXTENSION_VERSION2 (2) +#define HOOK_INTERFACE_VERSION (1) struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR); @@ -32,17 +33,26 @@ int read_fsmonitor_extension(struct index_state *istate, const void *data, uint32_t ewah_size; struct ewah_bitmap *fsmonitor_dirty; int ret; + uint64_t timestamp; + struct strbuf last_update = STRBUF_INIT; - if (sz < sizeof(uint32_t) + sizeof(uint64_t) + sizeof(uint32_t)) + if (sz < sizeof(uint32_t) + 1 + sizeof(uint32_t)) return error("corrupt fsmonitor extension (too short)"); hdr_version = get_be32(index); index += sizeof(uint32_t); - if (hdr_version != INDEX_EXTENSION_VERSION) + if (hdr_version == INDEX_EXTENSION_VERSION1) { + timestamp = get_be64(index); + strbuf_addf(&last_update, "%"PRIu64"", timestamp); + index += sizeof(uint64_t); + } else if (hdr_version == INDEX_EXTENSION_VERSION2) { + strbuf_addstr(&last_update, index); + index += last_update.len + 1; + } else { return error("bad fsmonitor version %d", hdr_version); + } - istate->fsmonitor_last_update = get_be64(index); - index += sizeof(uint64_t); + istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL); ewah_size = get_be32(index); index += sizeof(uint32_t); @@ -79,7 +89,6 @@ void fill_fsmonitor_bitmap(struct index_state *istate) void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate) { uint32_t hdr_version; - uint64_t tm; uint32_t ewah_start; uint32_t ewah_size = 0; int fixup = 0; @@ -89,11 +98,12 @@ void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate) BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)", (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); - put_be32(&hdr_version, INDEX_EXTENSION_VERSION); + put_be32(&hdr_version, INDEX_EXTENSION_VERSION2); strbuf_add(sb, &hdr_version, sizeof(uint32_t)); - put_be64(&tm, istate->fsmonitor_last_update); - strbuf_add(sb, &tm, sizeof(uint64_t)); + strbuf_addstr(sb, istate->fsmonitor_last_update); + strbuf_addch(sb, 0); /* Want to keep a NUL */ + fixup = sb->len; strbuf_add(sb, &ewah_size, sizeof(uint32_t)); /* we'll fix this up later */ @@ -110,9 +120,9 @@ void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate) } /* - * Call the query-fsmonitor hook passing the time of the last saved results. + * Call the query-fsmonitor hook passing the last update token of the saved results. */ -static int query_fsmonitor(int version, uint64_t last_update, struct strbuf *query_result) +static int query_fsmonitor(int version, const char *last_update, struct strbuf *query_result) { struct child_process cp = CHILD_PROCESS_INIT; @@ -121,7 +131,7 @@ static int query_fsmonitor(int version, uint64_t last_update, struct strbuf *que argv_array_push(&cp.args, core_fsmonitor); argv_array_pushf(&cp.args, "%d", version); - argv_array_pushf(&cp.args, "%" PRIuMAX, (uintmax_t)last_update); + argv_array_pushf(&cp.args, "%s", last_update); cp.use_shell = 1; cp.dir = get_git_work_tree(); @@ -151,6 +161,7 @@ void refresh_fsmonitor(struct index_state *istate) int query_success = 0; size_t bol; /* beginning of line */ uint64_t last_update; + struct strbuf last_update_token = STRBUF_INIT; char *buf; unsigned int i; @@ -164,6 +175,7 @@ void refresh_fsmonitor(struct index_state *istate) * should be inclusive to ensure we don't miss potential changes. */ last_update = getnanotime(); + strbuf_addf(&last_update_token, "%"PRIu64"", last_update); /* * If we have a last update time, call query_fsmonitor for the set of @@ -217,18 +229,21 @@ void refresh_fsmonitor(struct index_state *istate) } strbuf_release(&query_result); - /* Now that we've updated istate, save the last_update time */ - istate->fsmonitor_last_update = last_update; + /* Now that we've updated istate, save the last_update_token */ + FREE_AND_NULL(istate->fsmonitor_last_update); + istate->fsmonitor_last_update = strbuf_detach(&last_update_token, NULL); } void add_fsmonitor(struct index_state *istate) { unsigned int i; + struct strbuf last_update = STRBUF_INIT; if (!istate->fsmonitor_last_update) { trace_printf_key(&trace_fsmonitor, "add fsmonitor"); istate->cache_changed |= FSMONITOR_CHANGED; - istate->fsmonitor_last_update = getnanotime(); + strbuf_addf(&last_update, "%"PRIu64"", getnanotime()); + istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL); /* reset the fsmonitor state */ for (i = 0; i < istate->cache_nr; i++) @@ -250,7 +265,7 @@ void remove_fsmonitor(struct index_state *istate) if (istate->fsmonitor_last_update) { trace_printf_key(&trace_fsmonitor, "remove fsmonitor"); istate->cache_changed |= FSMONITOR_CHANGED; - istate->fsmonitor_last_update = 0; + FREE_AND_NULL(istate->fsmonitor_last_update); } } diff --git a/t/helper/test-dump-fsmonitor.c b/t/helper/test-dump-fsmonitor.c index 2786f47088..975f0ac890 100644 --- a/t/helper/test-dump-fsmonitor.c +++ b/t/helper/test-dump-fsmonitor.c @@ -13,7 +13,7 @@ int cmd__dump_fsmonitor(int ac, const char **av) printf("no fsmonitor\n"); return 0; } - printf("fsmonitor last update %"PRIuMAX"\n", (uintmax_t)istate->fsmonitor_last_update); + printf("fsmonitor last update %s\n", istate->fsmonitor_last_update); for (i = 0; i < istate->cache_nr; i++) printf((istate->cache[i]->ce_flags & CE_FSMONITOR_VALID) ? "+" : "-");
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