| 1 | /* |
| 2 | * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include "metadata-bucket.h" |
| 9 | |
| 10 | #include <common/buffer-view.h> |
| 11 | #include <common/consumer/consumer.h> |
| 12 | #include <common/dynamic-buffer.h> |
| 13 | #include <common/macros.h> |
| 14 | #include <common/error.h> |
| 15 | |
| 16 | struct metadata_bucket { |
| 17 | struct lttng_dynamic_buffer content; |
| 18 | struct { |
| 19 | metadata_bucket_flush_cb fn; |
| 20 | void *data; |
| 21 | } flush; |
| 22 | unsigned int buffer_count; |
| 23 | }; |
| 24 | |
| 25 | struct metadata_bucket *metadata_bucket_create( |
| 26 | metadata_bucket_flush_cb flush, void *data) |
| 27 | { |
| 28 | struct metadata_bucket *bucket; |
| 29 | |
| 30 | bucket = zmalloc(sizeof(typeof(*bucket))); |
| 31 | if (!bucket) { |
| 32 | PERROR("Failed to allocate buffer bucket"); |
| 33 | goto end; |
| 34 | } |
| 35 | |
| 36 | bucket->flush.fn = flush; |
| 37 | bucket->flush.data = data; |
| 38 | lttng_dynamic_buffer_init(&bucket->content); |
| 39 | end: |
| 40 | return bucket; |
| 41 | } |
| 42 | |
| 43 | void metadata_bucket_destroy(struct metadata_bucket *bucket) |
| 44 | { |
| 45 | if (!bucket) { |
| 46 | return; |
| 47 | } |
| 48 | |
| 49 | if (bucket->content.size > 0) { |
| 50 | WARN("Stream metadata bucket destroyed with remaining data: size = %zu, buffer count = %u", |
| 51 | bucket->content.size, bucket->buffer_count); |
| 52 | } |
| 53 | |
| 54 | lttng_dynamic_buffer_reset(&bucket->content); |
| 55 | free(bucket); |
| 56 | } |
| 57 | |
| 58 | void metadata_bucket_reset(struct metadata_bucket *bucket) |
| 59 | { |
| 60 | lttng_dynamic_buffer_reset(&bucket->content); |
| 61 | lttng_dynamic_buffer_init(&bucket->content); |
| 62 | bucket->buffer_count = 0; |
| 63 | } |
| 64 | |
| 65 | enum metadata_bucket_status metadata_bucket_fill(struct metadata_bucket *bucket, |
| 66 | const struct stream_subbuffer *buffer) |
| 67 | { |
| 68 | ssize_t ret; |
| 69 | struct lttng_buffer_view flushed_view; |
| 70 | struct stream_subbuffer flushed_subbuffer; |
| 71 | enum metadata_bucket_status status; |
| 72 | const bool should_flush = |
| 73 | LTTNG_OPTIONAL_GET(buffer->info.metadata.coherent); |
| 74 | const size_t padding_this_buffer = |
| 75 | buffer->info.metadata.padded_subbuf_size - |
| 76 | buffer->info.metadata.subbuf_size; |
| 77 | size_t flush_size; |
| 78 | |
| 79 | DBG("Metadata bucket filled with %zu bytes buffer view, sub-buffer size: %lu, padded sub-buffer size: %lu, coherent: %s", |
| 80 | buffer->buffer.buffer.size, |
| 81 | buffer->info.metadata.subbuf_size, |
| 82 | buffer->info.metadata.padded_subbuf_size, |
| 83 | buffer->info.metadata.coherent.value ? "true" : "false"); |
| 84 | /* |
| 85 | * If no metadata was accumulated and this buffer should be |
| 86 | * flushed, don't copy it unecessarily; just flush it directly. |
| 87 | */ |
| 88 | if (!should_flush || bucket->buffer_count != 0) { |
| 89 | /* |
| 90 | * Append the _padded_ subbuffer since they are combined |
| 91 | * into a single "virtual" subbuffer that will be |
| 92 | * flushed at once. |
| 93 | * |
| 94 | * This means that some padding will be sent over the |
| 95 | * network, but should not represent a large amount |
| 96 | * of data as incoherent subbuffers are typically |
| 97 | * pretty full. |
| 98 | * |
| 99 | * The padding of the last subbuffer (coherent) added to |
| 100 | * the bucket is not sent, which is what really matters |
| 101 | * from an efficiency point of view. |
| 102 | */ |
| 103 | ret = lttng_dynamic_buffer_append_view( |
| 104 | &bucket->content, &buffer->buffer.buffer); |
| 105 | if (ret) { |
| 106 | status = METADATA_BUCKET_STATUS_ERROR; |
| 107 | goto end; |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | bucket->buffer_count++; |
| 112 | if (!should_flush) { |
| 113 | status = METADATA_BUCKET_STATUS_OK; |
| 114 | goto end; |
| 115 | } |
| 116 | |
| 117 | flushed_view = bucket->content.size != 0 ? |
| 118 | lttng_buffer_view_from_dynamic_buffer(&bucket->content, 0, -1) : |
| 119 | lttng_buffer_view_from_view(&buffer->buffer.buffer, 0, -1); |
| 120 | |
| 121 | /* |
| 122 | * The flush is done with the size of all padded sub-buffers, except |
| 123 | * for the last one which we can safely "trim". The padding of the last |
| 124 | * packet will be reconstructed by the relay daemon. |
| 125 | */ |
| 126 | flush_size = flushed_view.size - padding_this_buffer; |
| 127 | |
| 128 | flushed_subbuffer = (typeof(flushed_subbuffer)) { |
| 129 | .buffer.buffer = flushed_view, |
| 130 | .info.metadata.subbuf_size = flush_size, |
| 131 | .info.metadata.padded_subbuf_size = flushed_view.size, |
| 132 | .info.metadata.version = buffer->info.metadata.version, |
| 133 | .info.metadata.coherent = buffer->info.metadata.coherent, |
| 134 | }; |
| 135 | |
| 136 | DBG("Metadata bucket flushing %zu bytes (%u sub-buffer%s)", |
| 137 | flushed_view.size, bucket->buffer_count, |
| 138 | bucket->buffer_count > 1 ? "s" : ""); |
| 139 | ret = bucket->flush.fn(&flushed_subbuffer, bucket->flush.data); |
| 140 | if (ret >= 0) { |
| 141 | status = METADATA_BUCKET_STATUS_OK; |
| 142 | } else { |
| 143 | status = METADATA_BUCKET_STATUS_ERROR; |
| 144 | } |
| 145 | |
| 146 | metadata_bucket_reset(bucket); |
| 147 | |
| 148 | end: |
| 149 | return status; |
| 150 | } |