dlls/hidclass.sys/buffer.c

   1 /*  Implementation of a ring buffer for reports
   2  *
   3  * Copyright 2015 CodeWeavers, Aric Stewart
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  18  */
  19
  20 #include "config.h"
  21 #include <stdarg.h>
  22 #define NONAMELESSUNION
  23 #include "hid.h"
  24
  25 #include "wine/debug.h"
  26
  27 WINE_DEFAULT_DEBUG_CHANNEL(hid);
  28
  29 #define POINTER_UNUSED 0xffffffff
  30 #define BASE_BUFFER_SIZE 32
  31 #define MIN_BUFFER_SIZE 2
  32 #define MAX_BUFFER_SIZE 512
  33
  34 struct ReportRingBuffer
  35 {
  36     UINT start, end, size;
  37
  38     UINT *pointers;
  39     UINT pointer_alloc;
  40     UINT buffer_size;
  41
  42     CRITICAL_SECTION lock;
  43
  44     BYTE *buffer;
  45 };
  46
  47 struct ReportRingBuffer* RingBuffer_Create(UINT buffer_size)
  48 {
  49     struct ReportRingBuffer *ring;
  50     int i;
  51
  52     TRACE("Create Ring Buffer with buffer size %i\n",buffer_size);
  53
  54     ring = HeapAlloc(GetProcessHeap(), 0, sizeof(*ring));
  55     if (!ring)
  56         return NULL;
  57     ring->start = ring->end = 0;
  58     ring->size = BASE_BUFFER_SIZE;
  59     ring->buffer_size = buffer_size;
  60     ring->pointer_alloc = 2;
  61     ring->pointers = HeapAlloc(GetProcessHeap(), 0, sizeof(UINT) * ring->pointer_alloc);
  62     if (!ring->pointers)
  63     {
  64         HeapFree(GetProcessHeap(), 0, ring);
  65         return NULL;
  66     }
  67     for (i = 0; i < ring->pointer_alloc; i++)
  68         ring->pointers[i] = POINTER_UNUSED;
  69     ring->buffer = HeapAlloc(GetProcessHeap(), 0, buffer_size * ring->size);
  70     if (!ring->buffer)
  71     {
  72         HeapFree(GetProcessHeap(), 0, ring->pointers);
  73         HeapFree(GetProcessHeap(), 0, ring);
  74         return NULL;
  75     }
  76     InitializeCriticalSection(&ring->lock);
  77     ring->lock.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": RingBuffer.lock");
  78     return ring;
  79 }
  80
  81 void RingBuffer_Destroy(struct ReportRingBuffer *ring)
  82 {
  83     HeapFree(GetProcessHeap(), 0, ring->buffer);
  84     HeapFree(GetProcessHeap(), 0, ring->pointers);
  85     ring->lock.DebugInfo->Spare[0] = 0;
  86     DeleteCriticalSection(&ring->lock);
  87     HeapFree(GetProcessHeap(), 0, ring);
  88 }
  89
  90 UINT RingBuffer_GetBufferSize(struct ReportRingBuffer *ring)
  91 {
  92     return ring->buffer_size;
  93 }
  94
  95 UINT RingBuffer_GetSize(struct ReportRingBuffer *ring)
  96 {
  97     return ring->size;
  98 }
  99
 100 NTSTATUS RingBuffer_SetSize(struct ReportRingBuffer *ring, UINT size)
 101 {
 102     BYTE* new_buffer;
 103     int i;
 104
 105     if (size < MIN_BUFFER_SIZE || size > MAX_BUFFER_SIZE)
 106         return STATUS_INVALID_PARAMETER;
 107     if (size == ring->size)
 108         return STATUS_SUCCESS;
 109
 110     EnterCriticalSection(&ring->lock);
 111     ring->start = ring->end = 0;
 112     for (i = 0; i < ring->pointer_alloc; i++)
 113     {
 114         if (ring->pointers[i] != POINTER_UNUSED)
 115             ring->pointers[i] = 0;
 116     }
 117     new_buffer = HeapAlloc(GetProcessHeap(), 0, ring->buffer_size * size);
 118     if (!new_buffer)
 119     {
 120         LeaveCriticalSection(&ring->lock);
 121         return STATUS_NO_MEMORY;
 122     }
 123     HeapFree(GetProcessHeap(), 0, ring->buffer);
 124     ring->buffer = new_buffer;
 125     ring->size = size;
 126     LeaveCriticalSection(&ring->lock);
 127     return STATUS_SUCCESS;
 128 }
 129
 130 void RingBuffer_Read(struct ReportRingBuffer *ring, UINT index, void *output, UINT *size)
 131 {
 132     void *ret = NULL;
 133
 134     EnterCriticalSection(&ring->lock);
 135     if (index >= ring->pointer_alloc || ring->pointers[index] == POINTER_UNUSED)
 136     {
 137         LeaveCriticalSection(&ring->lock);
 138         *size = 0;
 139         return;
 140     }
 141     if (ring->pointers[index] == ring->end)
 142     {
 143         LeaveCriticalSection(&ring->lock);
 144         *size = 0;
 145     }
 146     else
 147     {
 148         ret = &ring->buffer[ring->pointers[index] * ring->buffer_size];
 149         memcpy(output, ret, ring->buffer_size);
 150         ring->pointers[index]++;
 151         if (ring->pointers[index] == ring->size)
 152             ring->pointers[index] = 0;
 153         LeaveCriticalSection(&ring->lock);
 154         *size = ring->buffer_size;
 155     }
 156 }
 157
 158 UINT RingBuffer_AddPointer(struct ReportRingBuffer *ring)
 159 {
 160     UINT idx;
 161     EnterCriticalSection(&ring->lock);
 162     for (idx = 0; idx < ring->pointer_alloc; idx++)
 163         if (ring->pointers[idx] == POINTER_UNUSED)
 164             break;
 165     if (idx >= ring->pointer_alloc)
 166     {
 167         int count = idx = ring->pointer_alloc;
 168         ring->pointer_alloc *= 2;
 169         ring->pointers = HeapReAlloc(GetProcessHeap(), 0, ring->pointers, sizeof(UINT) * ring->pointer_alloc);
 170         for( ;count < ring->pointer_alloc; count++)
 171             ring->pointers[count] = POINTER_UNUSED;
 172     }
 173     ring->pointers[idx] = ring->end;
 174     LeaveCriticalSection(&ring->lock);
 175     return idx;
 176 }
 177
 178 void RingBuffer_RemovePointer(struct ReportRingBuffer *ring, UINT index)
 179 {
 180     EnterCriticalSection(&ring->lock);
 181     if (index < ring->pointer_alloc)
 182         ring->pointers[index] = POINTER_UNUSED;
 183     LeaveCriticalSection(&ring->lock);
 184 }
 185
 186 void RingBuffer_Write(struct ReportRingBuffer *ring, void *data)
 187 {
 188     UINT i;
 189
 190     EnterCriticalSection(&ring->lock);
 191     memcpy(&ring->buffer[ring->end * ring->buffer_size], data, ring->buffer_size);
 192     ring->end++;
 193     if (ring->end == ring->size)
 194         ring->end = 0;
 195     if (ring->start == ring->end)
 196     {
 197         ring->start++;
 198         if (ring->start == ring->size)
 199             ring->start = 0;
 200     }
 201     for (i = 0; i < ring->pointer_alloc; i++)
 202         if (ring->pointers[i] == ring->end)
 203             ring->pointers[i] = ring->start;
 204     LeaveCriticalSection(&ring->lock);
 205 }