23 #include "qemu/buffer.h"
34 static size_t buffer_req_size(Buffer *buffer, size_t len)  in buffer_req_size()  argument
37                pow2ceil(buffer->offset + len));  in buffer_req_size()
40 static void buffer_adj_size(Buffer *buffer, size_t len)  in buffer_adj_size()  argument
42     size_t old = buffer->capacity;  in buffer_adj_size()
43     buffer->capacity = buffer_req_size(buffer, len);  in buffer_adj_size()
44     buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);  in buffer_adj_size()
45     trace_buffer_resize(buffer->name ?: "unnamed",  in buffer_adj_size()
46                         old, buffer->capacity);  in buffer_adj_size()
48     /* make it even harder for the buffer to shrink, reset average size  in buffer_adj_size()
50     buffer->avg_size = MAX(buffer->avg_size,  in buffer_adj_size()
51                            buffer->capacity << BUFFER_AVG_SIZE_SHIFT);  in buffer_adj_size()
54 void buffer_init(Buffer *buffer, const char *name, ...)  in buffer_init()  argument
59     buffer->name = g_strdup_vprintf(name, ap);  in buffer_init()
63 static uint64_t buffer_get_avg_size(Buffer *buffer)  in buffer_get_avg_size()  argument
65     return buffer->avg_size >> BUFFER_AVG_SIZE_SHIFT;  in buffer_get_avg_size()
68 void buffer_shrink(Buffer *buffer)  in buffer_shrink()  argument
72     /* Calculate the average size of the buffer as  in buffer_shrink()
75     buffer->avg_size *= (1 << BUFFER_AVG_SIZE_SHIFT) - 1;  in buffer_shrink()
76     buffer->avg_size >>= BUFFER_AVG_SIZE_SHIFT;  in buffer_shrink()
77     buffer->avg_size += buffer_req_size(buffer, 0);  in buffer_shrink()
79     /* And then only shrink if the average size of the buffer is much  in buffer_shrink()
82     new = buffer_req_size(buffer, buffer_get_avg_size(buffer));  in buffer_shrink()
83     if (new < buffer->capacity >> 3 &&  in buffer_shrink()
85         buffer_adj_size(buffer, buffer_get_avg_size(buffer));  in buffer_shrink()
88     buffer_adj_size(buffer, 0);  in buffer_shrink()
91 void buffer_reserve(Buffer *buffer, size_t len)  in buffer_reserve()  argument
93     if ((buffer->capacity - buffer->offset) < len) {  in buffer_reserve()
94         buffer_adj_size(buffer, len);  in buffer_reserve()
98 gboolean buffer_empty(Buffer *buffer)  in buffer_empty()  argument
100     return buffer->offset == 0;  in buffer_empty()
103 uint8_t *buffer_end(Buffer *buffer)  in buffer_end()  argument
105     return buffer->buffer + buffer->offset;  in buffer_end()
108 void buffer_reset(Buffer *buffer)  in buffer_reset()  argument
110     buffer->offset = 0;  in buffer_reset()
111     buffer_shrink(buffer);  in buffer_reset()
114 void buffer_free(Buffer *buffer)  in buffer_free()  argument
116     trace_buffer_free(buffer->name ?: "unnamed", buffer->capacity);  in buffer_free()
117     g_free(buffer->buffer);  in buffer_free()
118     g_free(buffer->name);  in buffer_free()
119     buffer->offset = 0;  in buffer_free()
120     buffer->capacity = 0;  in buffer_free()
121     buffer->buffer = NULL;  in buffer_free()
122     buffer->name = NULL;  in buffer_free()
125 void buffer_append(Buffer *buffer, const void *data, size_t len)  in buffer_append()  argument
127     memcpy(buffer->buffer + buffer->offset, data, len);  in buffer_append()
128     buffer->offset += len;  in buffer_append()
131 void buffer_advance(Buffer *buffer, size_t len)  in buffer_advance()  argument
133     memmove(buffer->buffer, buffer->buffer + len,  in buffer_advance()
134             (buffer->offset - len));  in buffer_advance()
135     buffer->offset -= len;  in buffer_advance()
136     buffer_shrink(buffer);  in buffer_advance()
139 void buffer_move_empty(Buffer *to, Buffer *from)  in buffer_move_empty()
146     g_free(to->buffer);  in buffer_move_empty()
149     to->buffer = from->buffer;  in buffer_move_empty()
153     from->buffer = NULL;  in buffer_move_empty()
156 void buffer_move(Buffer *to, Buffer *from)  in buffer_move()
167     buffer_append(to, from->buffer, from->offset);  in buffer_move()
169     g_free(from->buffer);  in buffer_move()
172     from->buffer = NULL;  in buffer_move()