tools/perf/util/header.c

   1 #include <sys/types.h>
   2 #include <unistd.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5
   6 #include "util.h"
   7 #include "header.h"
   8
   9 /*
  10  *
  11  */
  12
  13 struct perf_header_attr *perf_header_attr__new(struct perf_counter_attr *attr)
  14 {
  15         struct perf_header_attr *self = malloc(sizeof(*self));
  16
  17         if (!self)
  18                 die("nomem");
  19
  20         self->attr = *attr;
  21         self->ids = 0;
  22         self->size = 1;
  23         self->id = malloc(sizeof(u64));
  24
  25         if (!self->id)
  26                 die("nomem");
  27
  28         return self;
  29 }
  30
  31 void perf_header_attr__add_id(struct perf_header_attr *self, u64 id)
  32 {
  33         int pos = self->ids;
  34
  35         self->ids++;
  36         if (self->ids > self->size) {
  37                 self->size *= 2;
  38                 self->id = realloc(self->id, self->size * sizeof(u64));
  39                 if (!self->id)
  40                         die("nomem");
  41         }
  42         self->id[pos] = id;
  43 }
  44
  45 /*
  46  *
  47  */
  48
  49 struct perf_header *perf_header__new(void)
  50 {
  51         struct perf_header *self = malloc(sizeof(*self));
  52
  53         if (!self)
  54                 die("nomem");
  55
  56         self->frozen = 0;
  57
  58         self->attrs = 0;
  59         self->size = 1;
  60         self->attr = malloc(sizeof(void *));
  61
  62         if (!self->attr)
  63                 die("nomem");
  64
  65         self->data_offset = 0;
  66         self->data_size = 0;
  67
  68         return self;
  69 }
  70
  71 void perf_header__add_attr(struct perf_header *self,
  72                            struct perf_header_attr *attr)
  73 {
  74         int pos = self->attrs;
  75
  76         if (self->frozen)
  77                 die("frozen");
  78
  79         self->attrs++;
  80         if (self->attrs > self->size) {
  81                 self->size *= 2;
  82                 self->attr = realloc(self->attr, self->size * sizeof(void *));
  83                 if (!self->attr)
  84                         die("nomem");
  85         }
  86         self->attr[pos] = attr;
  87 }
  88
  89 static const char *__perf_magic = "PERFFILE";
  90
  91 #define PERF_MAGIC      (*(u64 *)__perf_magic)
  92
  93 struct perf_file_section {
  94         u64 offset;
  95         u64 size;
  96 };
  97
  98 struct perf_file_attr {
  99         struct perf_counter_attr        attr;
 100         struct perf_file_section        ids;
 101 };
 102
 103 struct perf_file_header {
 104         u64                             magic;
 105         u64                             size;
 106         u64                             attr_size;
 107         struct perf_file_section        attrs;
 108         struct perf_file_section        data;
 109 };
 110
 111 static void do_write(int fd, void *buf, size_t size)
 112 {
 113         while (size) {
 114                 int ret = write(fd, buf, size);
 115
 116                 if (ret < 0)
 117                         die("failed to write");
 118
 119                 size -= ret;
 120                 buf += ret;
 121         }
 122 }
 123
 124 void perf_header__write(struct perf_header *self, int fd)
 125 {
 126         struct perf_file_header f_header;
 127         struct perf_file_attr   f_attr;
 128         struct perf_header_attr *attr;
 129         int i;
 130
 131         lseek(fd, sizeof(f_header), SEEK_SET);
 132
 133
 134         for (i = 0; i < self->attrs; i++) {
 135                 attr = self->attr[i];
 136
 137                 attr->id_offset = lseek(fd, 0, SEEK_CUR);
 138                 do_write(fd, attr->id, attr->ids * sizeof(u64));
 139         }
 140
 141
 142         self->attr_offset = lseek(fd, 0, SEEK_CUR);
 143
 144         for (i = 0; i < self->attrs; i++) {
 145                 attr = self->attr[i];
 146
 147                 f_attr = (struct perf_file_attr){
 148                         .attr = attr->attr,
 149                         .ids  = {
 150                                 .offset = attr->id_offset,
 151                                 .size   = attr->ids * sizeof(u64),
 152                         }
 153                 };
 154                 do_write(fd, &f_attr, sizeof(f_attr));
 155         }
 156
 157
 158         self->data_offset = lseek(fd, 0, SEEK_CUR);
 159
 160         f_header = (struct perf_file_header){
 161                 .magic     = PERF_MAGIC,
 162                 .size      = sizeof(f_header),
 163                 .attr_size = sizeof(f_attr),
 164                 .attrs = {
 165                         .offset = self->attr_offset,
 166                         .size   = self->attrs * sizeof(f_attr),
 167                 },
 168                 .data = {
 169                         .offset = self->data_offset,
 170                         .size   = self->data_size,
 171                 },
 172         };
 173
 174         lseek(fd, 0, SEEK_SET);
 175         do_write(fd, &f_header, sizeof(f_header));
 176         lseek(fd, self->data_offset + self->data_size, SEEK_SET);
 177
 178         self->frozen = 1;
 179 }
 180
 181 static void do_read(int fd, void *buf, size_t size)
 182 {
 183         while (size) {
 184                 int ret = read(fd, buf, size);
 185
 186                 if (ret < 0)
 187                         die("failed to read");
 188                 if (ret == 0)
 189                         die("failed to read: missing data");
 190
 191                 size -= ret;
 192                 buf += ret;
 193         }
 194 }
 195
 196 struct perf_header *perf_header__read(int fd)
 197 {
 198         struct perf_header      *self = perf_header__new();
 199         struct perf_file_header f_header;
 200         struct perf_file_attr   f_attr;
 201         u64                     f_id;
 202
 203         int nr_attrs, nr_ids, i, j;
 204
 205         lseek(fd, 0, SEEK_SET);
 206         do_read(fd, &f_header, sizeof(f_header));
 207
 208         if (f_header.magic      != PERF_MAGIC           ||
 209             f_header.size       != sizeof(f_header)     ||
 210             f_header.attr_size  != sizeof(f_attr))
 211                 die("incompatible file format");
 212
 213         nr_attrs = f_header.attrs.size / sizeof(f_attr);
 214         lseek(fd, f_header.attrs.offset, SEEK_SET);
 215
 216         for (i = 0; i < nr_attrs; i++) {
 217                 struct perf_header_attr *attr;
 218                 off_t tmp;
 219
 220                 do_read(fd, &f_attr, sizeof(f_attr));
 221                 tmp = lseek(fd, 0, SEEK_CUR);
 222
 223                 attr = perf_header_attr__new(&f_attr.attr);
 224
 225                 nr_ids = f_attr.ids.size / sizeof(u64);
 226                 lseek(fd, f_attr.ids.offset, SEEK_SET);
 227
 228                 for (j = 0; j < nr_ids; j++) {
 229                         do_read(fd, &f_id, sizeof(f_id));
 230
 231                         perf_header_attr__add_id(attr, f_id);
 232                 }
 233                 perf_header__add_attr(self, attr);
 234                 lseek(fd, tmp, SEEK_SET);
 235         }
 236
 237         self->data_offset = f_header.data.offset;
 238         self->data_size   = f_header.data.size;
 239
 240         lseek(fd, self->data_offset + self->data_size, SEEK_SET);
 241
 242         self->frozen = 1;
 243
 244         return self;
 245 }