Merge pull request #9104 from tagcup/zstd

Add zstd compression support.

1 files changed, 194 insertions, 0 deletions

diff --git a/thirdparty/zstd/common/pool.c b/thirdparty/zstd/common/pool.c
new file mode 100644
index 0000000000..e439fe1b0d
--- /dev/null
+++ b/thirdparty/zstd/common/pool.c
@@ -0,0 +1,194 @@
+/**
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+
+/* ======   Dependencies   ======= */
+#include <stddef.h>  /* size_t */
+#include <stdlib.h>  /* malloc, calloc, free */
+#include "pool.h"
+
+/* ======   Compiler specifics   ====== */
+#if defined(_MSC_VER)
+#  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */
+#endif
+
+
+#ifdef ZSTD_MULTITHREAD
+
+#include "threading.h"   /* pthread adaptation */
+
+/* A job is a function and an opaque argument */
+typedef struct POOL_job_s {
+  POOL_function function;
+  void *opaque;
+} POOL_job;
+
+struct POOL_ctx_s {
+    /* Keep track of the threads */
+    pthread_t *threads;
+    size_t numThreads;
+
+    /* The queue is a circular buffer */
+    POOL_job *queue;
+    size_t queueHead;
+    size_t queueTail;
+    size_t queueSize;
+    /* The mutex protects the queue */
+    pthread_mutex_t queueMutex;
+    /* Condition variable for pushers to wait on when the queue is full */
+    pthread_cond_t queuePushCond;
+    /* Condition variables for poppers to wait on when the queue is empty */
+    pthread_cond_t queuePopCond;
+    /* Indicates if the queue is shutting down */
+    int shutdown;
+};
+
+/* POOL_thread() :
+   Work thread for the thread pool.
+   Waits for jobs and executes them.
+   @returns : NULL on failure else non-null.
+*/
+static void* POOL_thread(void* opaque) {
+    POOL_ctx* const ctx = (POOL_ctx*)opaque;
+    if (!ctx) { return NULL; }
+    for (;;) {
+        /* Lock the mutex and wait for a non-empty queue or until shutdown */
+        pthread_mutex_lock(&ctx->queueMutex);
+        while (ctx->queueHead == ctx->queueTail && !ctx->shutdown) {
+            pthread_cond_wait(&ctx->queuePopCond, &ctx->queueMutex);
+        }
+        /* empty => shutting down: so stop */
+        if (ctx->queueHead == ctx->queueTail) {
+            pthread_mutex_unlock(&ctx->queueMutex);
+            return opaque;
+        }
+        /* Pop a job off the queue */
+        {   POOL_job const job = ctx->queue[ctx->queueHead];
+            ctx->queueHead = (ctx->queueHead + 1) % ctx->queueSize;
+            /* Unlock the mutex, signal a pusher, and run the job */
+            pthread_mutex_unlock(&ctx->queueMutex);
+            pthread_cond_signal(&ctx->queuePushCond);
+            job.function(job.opaque);
+        }
+    }
+    /* Unreachable */
+}
+
+POOL_ctx *POOL_create(size_t numThreads, size_t queueSize) {
+    POOL_ctx *ctx;
+    /* Check the parameters */
+    if (!numThreads || !queueSize) { return NULL; }
+    /* Allocate the context and zero initialize */
+    ctx = (POOL_ctx *)calloc(1, sizeof(POOL_ctx));
+    if (!ctx) { return NULL; }
+    /* Initialize the job queue.
+     * It needs one extra space since one space is wasted to differentiate empty
+     * and full queues.
+     */
+    ctx->queueSize = queueSize + 1;
+    ctx->queue = (POOL_job *)malloc(ctx->queueSize * sizeof(POOL_job));
+    ctx->queueHead = 0;
+    ctx->queueTail = 0;
+    pthread_mutex_init(&ctx->queueMutex, NULL);
+    pthread_cond_init(&ctx->queuePushCond, NULL);
+    pthread_cond_init(&ctx->queuePopCond, NULL);
+    ctx->shutdown = 0;
+    /* Allocate space for the thread handles */
+    ctx->threads = (pthread_t *)malloc(numThreads * sizeof(pthread_t));
+    ctx->numThreads = 0;
+    /* Check for errors */
+    if (!ctx->threads || !ctx->queue) { POOL_free(ctx); return NULL; }
+    /* Initialize the threads */
+    {   size_t i;
+        for (i = 0; i < numThreads; ++i) {
+            if (pthread_create(&ctx->threads[i], NULL, &POOL_thread, ctx)) {
+                ctx->numThreads = i;
+                POOL_free(ctx);
+                return NULL;
+        }   }
+        ctx->numThreads = numThreads;
+    }
+    return ctx;
+}
+
+/*! POOL_join() :
+    Shutdown the queue, wake any sleeping threads, and join all of the threads.
+*/
+static void POOL_join(POOL_ctx *ctx) {
+    /* Shut down the queue */
+    pthread_mutex_lock(&ctx->queueMutex);
+    ctx->shutdown = 1;
+    pthread_mutex_unlock(&ctx->queueMutex);
+    /* Wake up sleeping threads */
+    pthread_cond_broadcast(&ctx->queuePushCond);
+    pthread_cond_broadcast(&ctx->queuePopCond);
+    /* Join all of the threads */
+    {   size_t i;
+        for (i = 0; i < ctx->numThreads; ++i) {
+            pthread_join(ctx->threads[i], NULL);
+    }   }
+}
+
+void POOL_free(POOL_ctx *ctx) {
+    if (!ctx) { return; }
+    POOL_join(ctx);
+    pthread_mutex_destroy(&ctx->queueMutex);
+    pthread_cond_destroy(&ctx->queuePushCond);
+    pthread_cond_destroy(&ctx->queuePopCond);
+    if (ctx->queue) free(ctx->queue);
+    if (ctx->threads) free(ctx->threads);
+    free(ctx);
+}
+
+void POOL_add(void *ctxVoid, POOL_function function, void *opaque) {
+    POOL_ctx *ctx = (POOL_ctx *)ctxVoid;
+    if (!ctx) { return; }
+
+    pthread_mutex_lock(&ctx->queueMutex);
+    {   POOL_job const job = {function, opaque};
+        /* Wait until there is space in the queue for the new job */
+        size_t newTail = (ctx->queueTail + 1) % ctx->queueSize;
+        while (ctx->queueHead == newTail && !ctx->shutdown) {
+          pthread_cond_wait(&ctx->queuePushCond, &ctx->queueMutex);
+          newTail = (ctx->queueTail + 1) % ctx->queueSize;
+        }
+        /* The queue is still going => there is space */
+        if (!ctx->shutdown) {
+            ctx->queue[ctx->queueTail] = job;
+            ctx->queueTail = newTail;
+        }
+    }
+    pthread_mutex_unlock(&ctx->queueMutex);
+    pthread_cond_signal(&ctx->queuePopCond);
+}
+
+#else  /* ZSTD_MULTITHREAD  not defined */
+/* No multi-threading support */
+
+/* We don't need any data, but if it is empty malloc() might return NULL. */
+struct POOL_ctx_s {
+  int data;
+};
+
+POOL_ctx *POOL_create(size_t numThreads, size_t queueSize) {
+  (void)numThreads;
+  (void)queueSize;
+  return (POOL_ctx *)malloc(sizeof(POOL_ctx));
+}
+
+void POOL_free(POOL_ctx *ctx) {
+  if (ctx) free(ctx);
+}
+
+void POOL_add(void *ctx, POOL_function function, void *opaque) {
+  (void)ctx;
+  function(opaque);
+}
+
+#endif  /* ZSTD_MULTITHREAD */