X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=bluesky%2Fstore.c;h=ac9bc96f7b21603805bdfc25dae4bb56304f3c32;hb=8ff0fd08d6e1cc97cdb7e94b7cd97dc28c29e674;hp=9e0fca1e631c725912e35fd8159e972e1cb65ba8;hpb=07eac8709bced5f814a65fa0d5dd62e4bd649a9a;p=bluesky.git

diff --git a/bluesky/store.c b/bluesky/store.c
index 9e0fca1..ac9bc96 100644
--- a/bluesky/store.c
+++ b/bluesky/store.c
@@ -3,26 +3,62 @@
  * Copyright (C) 2009  The Regents of the University of California
  * Written by Michael Vrable <mvrable@cs.ucsd.edu>
  *
- * TODO: Licensing
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
  */
 
 #include <stdint.h>
 #include <glib.h>
 #include <string.h>
 
-#include "bluesky.h"
+#include "bluesky-private.h"
 
 /* Interaction with cloud storage.  We expose very simple GET/PUT style
  * interface, which different backends can implement.  Available backends
- * (will) include Amazon S3 and a simple local store for testing purposes. */
+ * (will) include Amazon S3 and a simple local store for testing purposes.
+ * Operations may be performed asynchronously. */
 
-struct _BlueSkyStore {
+struct BlueSkyStore {
     const BlueSkyStoreImplementation *impl;
     gpointer handle;
+
+    GMutex *lock;
+    GCond *cond_idle;
+    int pending;                /* Count of operations not yet complete. */
+
+    struct bluesky_stats *stats_get, *stats_put;
 };
 
 GHashTable *store_implementations;
 
+/* Thread pool for calling notifier functions when an operation completes.
+ * These are called in a separate thread for locking reasons: we want to call
+ * the notifiers without the lock on the async object held, but completion
+ * occurs when the lock is held--so we need some way to defer the call.  This
+ * isn't really optimal from a cache-locality standpoint. */
+static GThreadPool *notifier_thread_pool;
+
 void bluesky_store_register(const BlueSkyStoreImplementation *impl,
                             const gchar *name)
 {
@@ -33,17 +69,37 @@ BlueSkyStore *bluesky_store_new(const gchar *type)
 {
     const BlueSkyStoreImplementation *impl;
 
-    impl = g_hash_table_lookup(store_implementations, type);
-    if (impl == NULL)
+    gchar *scheme, *path;
+    scheme = g_strdup(type);
+    path = strchr(scheme, ':');
+    if (path != NULL) {
+        *path = '\0';
+        path++;
+    }
+
+    impl = g_hash_table_lookup(store_implementations, scheme);
+    if (impl == NULL) {
+        g_free(scheme);
         return NULL;
+    }
 
-    gpointer handle = impl->create();
-    if (handle == NULL)
+    gpointer handle = impl->create(path);
+    if (handle == NULL) {
+        g_free(scheme);
         return NULL;
+    }
 
     BlueSkyStore *store = g_new(BlueSkyStore, 1);
     store->impl = impl;
     store->handle = handle;
+    store->lock = g_mutex_new();
+    store->cond_idle = g_cond_new();
+    store->pending = 0;
+    store->stats_get = bluesky_stats_new(g_strdup_printf("Store[%s]: GETS",
+                                                         type));
+    store->stats_put = bluesky_stats_new(g_strdup_printf("Store[%s]: PUTS",
+                                                         type));
+    g_free(scheme);
     return store;
 }
 
@@ -53,70 +109,339 @@ void bluesky_store_free(BlueSkyStore *store)
     g_free(store);
 }
 
-BlueSkyRCStr *bluesky_store_get(BlueSkyStore *store, const gchar *key)
+char *bluesky_store_lookup_last(BlueSkyStore *store, const char *prefix)
 {
-    return store->impl->get(store->handle, key);
+    return store->impl->lookup_last(store->handle, prefix);
 }
 
-void bluesky_store_put(BlueSkyStore *store,
-                       const gchar *key, BlueSkyRCStr *val)
+BlueSkyStoreAsync *bluesky_store_async_new(BlueSkyStore *store)
 {
-    store->impl->put(store->handle, key, val);
+    BlueSkyStoreAsync *async;
+
+    async = g_new(BlueSkyStoreAsync, 1);
+    async->store = store;
+    async->lock = g_mutex_new();
+    async->completion_cond = g_cond_new();
+    async->refcount = 1;
+    async->status = ASYNC_NEW;
+    async->op = STORE_OP_NONE;
+    async->key = NULL;
+    async->data = NULL;
+    async->start = async->len = 0;
+    async->range_done = FALSE;
+    async->result = -1;
+    async->notifiers = NULL;
+    async->notifier_count = 0;
+    async->barrier = NULL;
+    async->store_private = NULL;
+    async->profile = NULL;
+
+    return async;
 }
 
-/* Create and return a new reference-counted string.  The reference count is
- * initially one.  The newly-returned string takes ownership of the memory
- * pointed at by data, and will call g_free on it when the reference count
- * drops to zero. */
-BlueSkyRCStr *bluesky_string_new(gpointer data, gsize len)
+gpointer bluesky_store_async_get_handle(BlueSkyStoreAsync *async)
 {
-    BlueSkyRCStr *string = g_new(BlueSkyRCStr, 1);
-    string->data = data;
-    string->len = len;
-    g_atomic_int_set(&string->refcount, 1);
-    return string;
+    return async->store->handle;
 }
 
-void bluesky_string_ref(BlueSkyRCStr *string)
+void bluesky_store_async_ref(BlueSkyStoreAsync *async)
 {
-    if (string == NULL)
+    if (async == NULL)
         return;
 
-    g_atomic_int_inc(&string->refcount);
+    g_return_if_fail(g_atomic_int_get(&async->refcount) > 0);
+
+    g_atomic_int_inc(&async->refcount);
 }
 
-void bluesky_string_unref(BlueSkyRCStr *string)
+void bluesky_store_async_unref(BlueSkyStoreAsync *async)
 {
-    if (string == NULL)
+    if (async == NULL)
         return;
 
-    if (g_atomic_int_dec_and_test(&string->refcount)) {
-        g_free(string->data);
-        g_free(string);
+    if (g_atomic_int_dec_and_test(&async->refcount)) {
+        async->store->impl->cleanup(async->store->handle, async);
+        g_mutex_free(async->lock);
+        g_cond_free(async->completion_cond);
+        g_free(async->key);
+        bluesky_string_unref(async->data);
+        g_free(async);
     }
 }
 
-/* Duplicate and return a new reference-counted string, containing a copy of
- * the original data, with a reference count of 1.  As an optimization, if the
- * passed-in string already has a reference count of 1, the original is
- * returned.   Can be used to make a mutable copy of a shared string.  For this
- * to truly be safe, it is probably needed that there be some type of lock
- * protecting access to the string. */
-BlueSkyRCStr *bluesky_string_dup(BlueSkyRCStr *string)
+/* Block until the given operation has completed. */
+void bluesky_store_async_wait(BlueSkyStoreAsync *async)
 {
-    if (string == NULL)
-        return NULL;
+    g_return_if_fail(async != NULL);
+    g_mutex_lock(async->lock);
 
-    if (g_atomic_int_dec_and_test(&string->refcount)) {
-        /* There are no other shared copies, so return this one. */
-        g_atomic_int_inc(&string->refcount);
-        return string;
+    if (async->status == ASYNC_NEW) {
+        g_error("bluesky_store_async_wait on a new async object!\n");
+        g_mutex_unlock(async->lock);
+        return;
+    }
+
+    while (async->status != ASYNC_COMPLETE
+           || g_atomic_int_get(&async->notifier_count) > 0) {
+        g_cond_wait(async->completion_cond, async->lock);
+    }
+
+    g_mutex_unlock(async->lock);
+}
+
+/* Add a notifier function to be called when the operation completes. */
+void bluesky_store_async_add_notifier(BlueSkyStoreAsync *async,
+                                      GFunc func, gpointer user_data)
+{
+    struct BlueSkyNotifierList *nl = g_new(struct BlueSkyNotifierList, 1);
+    g_mutex_lock(async->lock);
+    nl->next = async->notifiers;
+    nl->func = func;
+    nl->async = async; bluesky_store_async_ref(async);
+    nl->user_data = user_data;
+    g_atomic_int_inc(&async->notifier_count);
+    if (async->status == ASYNC_COMPLETE) {
+        g_thread_pool_push(notifier_thread_pool, nl, NULL);
     } else {
-        return bluesky_string_new(g_memdup(string->data, string->len),
-                                  string->len);
+        async->notifiers = nl;
+    }
+    g_mutex_unlock(async->lock);
+}
+
+static void op_complete(gpointer a, gpointer b)
+{
+    BlueSkyStoreAsync *barrier = (BlueSkyStoreAsync *)b;
+
+    bluesky_store_async_ref(barrier);
+    g_mutex_lock(barrier->lock);
+    barrier->store_private
+        = GINT_TO_POINTER(GPOINTER_TO_INT(barrier->store_private) - 1);
+    if (GPOINTER_TO_INT(barrier->store_private) == 0
+            && barrier->status != ASYNC_NEW) {
+        bluesky_store_async_mark_complete(barrier);
+    }
+    g_mutex_unlock(barrier->lock);
+    bluesky_store_async_unref(barrier);
+}
+
+/* Mark an asynchronous operation as complete.  This should only be called by
+ * the store implementations.  The lock should be held when calling this
+ * function.  Any notifier functions will be called, but in a separate thread
+ * and without the lock held. */
+void bluesky_store_async_mark_complete(BlueSkyStoreAsync *async)
+{
+    g_return_if_fail(async->status != ASYNC_COMPLETE);
+
+    bluesky_time_hires elapsed = bluesky_now_hires() - async->start_time;
+    bluesky_time_hires latency = bluesky_now_hires() - async->exec_time;
+
+    if (async->op != STORE_OP_BARRIER) {
+        g_mutex_lock(async->store->lock);
+        async->store->pending--;
+        if (async->store->pending == 0)
+            g_cond_broadcast(async->store->cond_idle);
+        g_mutex_unlock(async->store->lock);
+    }
+
+    /* If the request was a range request but the backend read the entire
+     * object, select out the appropriate bytes. */
+    if (async->op == STORE_OP_GET
+            && !async->range_done
+            && async->result == 0
+            && async->data != NULL) {
+        if (async->start != 0 || async->len != 0) {
+            /* If the caller requesteda read outside the object, return an
+             * error. */
+            if (async->start + async->len > async->data->len) {
+                g_warning("Range request outside object boundaries!\n");
+                async->result = -1;
+            } else {
+                if (async->len == 0)
+                    async->len = async->data->len - async->start;
+                BlueSkyRCStr *newstr = bluesky_string_new(g_memdup(&async->data->data[async->start], async->len), async->len);
+                bluesky_string_unref(async->data);
+                async->data = newstr;
+                async->range_done = TRUE;
+            }
+        }
+    }
+
+    async->status = ASYNC_COMPLETE;
+    g_cond_broadcast(async->completion_cond);
+
+    if (async->barrier != NULL && async->notifiers == NULL)
+        op_complete(async, async->barrier);
+
+    while (async->notifiers != NULL) {
+        struct BlueSkyNotifierList *nl = async->notifiers;
+        async->notifiers = nl->next;
+        g_thread_pool_push(notifier_thread_pool, nl, NULL);
+    }
+
+    if (async->profile) {
+        bluesky_profile_add_event(
+            async->profile,
+            g_strdup_printf("%s for %s complete",
+                            async->op == STORE_OP_GET ? "GET"
+                            : async->op == STORE_OP_PUT ? "PUT"
+                            : async->op == STORE_OP_DELETE ? "DELETE"
+                            : async->op == STORE_OP_BARRIER ? "BARRIER" : "???",
+                            async->key)
+        );
+    }
+
+    if (bluesky_verbose) {
+        g_log("bluesky/store", G_LOG_LEVEL_DEBUG,
+              "[%p] complete: elapsed = %"PRIi64" ns, latency = %"PRIi64" ns",
+              async, elapsed, latency);
+    }
+
+    if (async->data) {
+        if (async->op == STORE_OP_GET) {
+            bluesky_stats_add(async->store->stats_get, async->data->len);
+        } else if (async->op == STORE_OP_PUT) {
+            bluesky_stats_add(async->store->stats_put, async->data->len);
+        }
+    }
+}
+
+void bluesky_store_async_submit(BlueSkyStoreAsync *async)
+{
+    BlueSkyStore *store = async->store;
+
+    async->start_time = bluesky_now_hires();
+
+    // Backends should fill this in with a better estimate of the actual time
+    // processing was started, if there could be a delay from submission time.
+    async->exec_time = bluesky_now_hires();
+
+    if (async->profile) {
+        bluesky_profile_add_event(
+            async->profile,
+            g_strdup_printf("Start %s for %s",
+                            async->op == STORE_OP_GET ? "GET"
+                            : async->op == STORE_OP_PUT ? "PUT"
+                            : async->op == STORE_OP_DELETE ? "DELETE"
+                            : async->op == STORE_OP_BARRIER ? "BARRIER" : "???",
+                            async->key)
+        );
+    }
+
+    if (bluesky_verbose) {
+        g_log("bluesky/store", G_LOG_LEVEL_DEBUG, "[%p] submit: %s %s",
+              async,
+              async->op == STORE_OP_GET ? "GET"
+                : async->op == STORE_OP_PUT ? "PUT"
+                : async->op == STORE_OP_DELETE ? "DELETE"
+                : async->op == STORE_OP_BARRIER ? "BARRIER" : "???",
+              async->key);
+    }
+
+    /* Barriers are handled specially, and not handed down the storage
+     * implementation layer. */
+    if (async->op == STORE_OP_BARRIER) {
+        async->status = ASYNC_RUNNING;
+        if (GPOINTER_TO_INT(async->store_private) == 0)
+            bluesky_store_async_mark_complete(async);
+        return;
+    }
+
+    g_mutex_lock(async->store->lock);
+    async->store->pending++;
+    g_mutex_unlock(async->store->lock);
+
+    store->impl->submit(store->handle, async);
+
+    if (bluesky_options.synchronous_stores)
+        bluesky_store_async_wait(async);
+}
+
+/* Add the given operation to the barrier.  The barrier will not complete until
+ * all operations added to it have completed. */
+void bluesky_store_add_barrier(BlueSkyStoreAsync *barrier,
+                               BlueSkyStoreAsync *async)
+{
+    g_return_if_fail(barrier->op == STORE_OP_BARRIER);
+
+    g_mutex_lock(barrier->lock);
+    barrier->store_private
+        = GINT_TO_POINTER(GPOINTER_TO_INT(barrier->store_private) + 1);
+    g_mutex_unlock(barrier->lock);
+
+    g_mutex_lock(async->lock);
+    if (async->barrier == NULL && async->status != ASYNC_COMPLETE) {
+        async->barrier = barrier;
+        g_mutex_unlock(async->lock);
+    } else {
+        if (async->barrier != NULL)
+            g_warning("Adding async to more than one barrier!\n");
+        g_mutex_unlock(async->lock);
+        bluesky_store_async_add_notifier(async, op_complete, barrier);
+    }
+}
+
+static void notifier_task(gpointer n, gpointer s)
+{
+    struct BlueSkyNotifierList *notifier = (struct BlueSkyNotifierList *)n;
+
+    notifier->func(notifier->async, notifier->user_data);
+    if (g_atomic_int_dec_and_test(&notifier->async->notifier_count)) {
+        g_mutex_lock(notifier->async->lock);
+        if (notifier->async->barrier != NULL)
+            op_complete(notifier->async, notifier->async->barrier);
+        g_cond_broadcast(notifier->async->completion_cond);
+        g_mutex_unlock(notifier->async->lock);
+    }
+    bluesky_store_async_unref(notifier->async);
+    g_free(notifier);
+}
+
+void bluesky_store_sync(BlueSkyStore *store)
+{
+    g_mutex_lock(store->lock);
+    if (bluesky_verbose) {
+        g_log("bluesky/store", G_LOG_LEVEL_DEBUG,
+              "Waiting for pending store operations to complete...");
+    }
+    while (store->pending > 0) {
+        g_cond_wait(store->cond_idle, store->lock);
+    }
+    g_mutex_unlock(store->lock);
+    if (bluesky_verbose) {
+        g_log("bluesky/store", G_LOG_LEVEL_DEBUG, "Operations are complete.");
     }
 }
 
+/* Convenience wrappers that perform a single operation synchronously. */
+BlueSkyRCStr *bluesky_store_get(BlueSkyStore *store, const gchar *key)
+{
+    BlueSkyStoreAsync *async = bluesky_store_async_new(store);
+    async->op = STORE_OP_GET;
+    async->key = g_strdup(key);
+    bluesky_store_async_submit(async);
+
+    bluesky_store_async_wait(async);
+
+    BlueSkyRCStr *data = async->data;
+    bluesky_string_ref(data);
+    bluesky_store_async_unref(async);
+    return data;
+}
+
+void bluesky_store_put(BlueSkyStore *store,
+                       const gchar *key, BlueSkyRCStr *val)
+{
+    BlueSkyStoreAsync *async = bluesky_store_async_new(store);
+    async->op = STORE_OP_PUT;
+    async->key = g_strdup(key);
+    bluesky_string_ref(val);
+    async->data = val;
+    bluesky_store_async_submit(async);
+
+    bluesky_store_async_wait(async);
+    bluesky_store_async_unref(async);
+}
+
 /* Simple in-memory data store for test purposes. */
 typedef struct {
     GMutex *lock;
@@ -125,7 +450,7 @@ typedef struct {
     GHashTable *store;
 } MemStore;
 
-static gpointer memstore_create()
+static gpointer memstore_create(const gchar *path)
 {
     MemStore *store = g_new(MemStore, 1);
     store->lock = g_mutex_new();
@@ -157,15 +482,41 @@ static void memstore_put(gpointer s, const gchar *key, BlueSkyRCStr *val)
     g_hash_table_insert(store->store, g_strdup(key), val);
 }
 
+static void memstore_submit(gpointer s, BlueSkyStoreAsync *async)
+{
+    g_return_if_fail(async->status == ASYNC_NEW);
+    g_return_if_fail(async->op != STORE_OP_NONE);
+
+    switch (async->op) {
+    case STORE_OP_GET:
+        async->data = memstore_get(s, async->key);
+        break;
+
+    case STORE_OP_PUT:
+        memstore_put(s, async->key, async->data);
+        break;
+
+    default:
+        g_warning("Uknown operation type for MemStore: %d\n", async->op);
+        return;
+    }
+
+    bluesky_store_async_mark_complete(async);
+}
+
+static void memstore_cleanup(gpointer store, BlueSkyStoreAsync *async)
+{
+}
+
 static BlueSkyStoreImplementation memstore_impl = {
     .create = memstore_create,
     .destroy = memstore_destroy,
-    .get = memstore_get,
-    .put = memstore_put,
+    .submit = memstore_submit,
+    .cleanup = memstore_cleanup,
 };
 
 /* Store implementation which writes data as files to disk. */
-static gpointer filestore_create()
+static gpointer filestore_create(const gchar *path)
 {
     return GINT_TO_POINTER(1);
 }
@@ -174,7 +525,7 @@ static void filestore_destroy()
 {
 }
 
-static BlueSkyRCStr *filestore_get(gpointer s, const gchar *key)
+static BlueSkyRCStr *filestore_get(const gchar *key)
 {
     gchar *contents = NULL;
     gsize length;
@@ -187,21 +538,102 @@ static BlueSkyRCStr *filestore_get(gpointer s, const gchar *key)
     return bluesky_string_new(contents, length);
 }
 
-static void filestore_put(gpointer s, const gchar *key, BlueSkyRCStr *val)
+static void filestore_put(const gchar *key, BlueSkyRCStr *val)
 {
     g_file_set_contents(key, val->data, val->len, NULL);
 }
 
+static void filestore_submit(gpointer s, BlueSkyStoreAsync *async)
+{
+    g_return_if_fail(async->status == ASYNC_NEW);
+    g_return_if_fail(async->op != STORE_OP_NONE);
+
+    switch (async->op) {
+    case STORE_OP_GET:
+        async->data = filestore_get(async->key);
+        async->result = 0;
+        break;
+
+    case STORE_OP_PUT:
+        filestore_put(async->key, async->data);
+        async->result = 0;
+        break;
+
+    default:
+        g_warning("Uknown operation type for FileStore: %d\n", async->op);
+        return;
+    }
+
+    bluesky_store_async_mark_complete(async);
+}
+
+static void filestore_cleanup(gpointer store, BlueSkyStoreAsync *async)
+{
+}
+
+static char *filestore_lookup_last(gpointer store, const char *prefix)
+{
+    char *last = NULL;
+    GDir *dir = g_dir_open(".", 0, NULL);
+    if (dir == NULL) {
+        g_warning("Unable to open directory for listing");
+        return NULL;
+    }
+
+    const gchar *file;
+    while ((file = g_dir_read_name(dir)) != NULL) {
+        if (strncmp(file, prefix, strlen(prefix)) == 0) {
+            if (last == NULL || strcmp(file, last) > 0) {
+                g_free(last);
+                last = g_strdup(file);
+            }
+        }
+    }
+    g_dir_close(dir);
+
+    return last;
+}
+
 static BlueSkyStoreImplementation filestore_impl = {
     .create = filestore_create,
     .destroy = filestore_destroy,
-    .get = filestore_get,
-    .put = filestore_put,
+    .submit = filestore_submit,
+    .cleanup = filestore_cleanup,
+    .lookup_last = filestore_lookup_last,
+};
+
+/* A store implementation which simply discards all data, for testing. */
+static gpointer nullstore_create(const gchar *path)
+{
+    return (gpointer)nullstore_create;
+}
+
+static void nullstore_destroy(gpointer store)
+{
+}
+
+static void nullstore_submit(gpointer s, BlueSkyStoreAsync *async)
+{
+    bluesky_store_async_mark_complete(async);
+}
+
+static void nullstore_cleanup(gpointer store, BlueSkyStoreAsync *async)
+{
+}
+
+static BlueSkyStoreImplementation nullstore_impl = {
+    .create = nullstore_create,
+    .destroy = nullstore_destroy,
+    .submit = nullstore_submit,
+    .cleanup = nullstore_cleanup,
 };
 
 void bluesky_store_init()
 {
     store_implementations = g_hash_table_new(g_str_hash, g_str_equal);
+    notifier_thread_pool = g_thread_pool_new(notifier_task, NULL,
+                                             bluesky_max_threads, FALSE, NULL);
     bluesky_store_register(&memstore_impl, "mem");
     bluesky_store_register(&filestore_impl, "file");
+    bluesky_store_register(&nullstore_impl, "null");
 }