Select Git revision
qstr.c 13.88 KiB
/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <assert.h>
#include <string.h>
#include <stdio.h>
#include "py/mpstate.h"
#include "py/qstr.h"
#include "py/gc.h"
#include "py/runtime.h"
// NOTE: we are using linear arrays to store and search for qstr's (unique strings, interned strings)
// ultimately we will replace this with a static hash table of some kind
#if MICROPY_DEBUG_VERBOSE // print debugging info
#define DEBUG_printf DEBUG_printf
#else // don't print debugging info
#define DEBUG_printf(...) (void)0
#endif
// A qstr is an index into the qstr pool.
// The data for a qstr is \0 terminated (so they can be printed using printf)
#define Q_HASH_MASK ((1 << (8 * MICROPY_QSTR_BYTES_IN_HASH)) - 1)
#if MICROPY_PY_THREAD && !MICROPY_PY_THREAD_GIL
#define QSTR_ENTER() mp_thread_mutex_lock(&MP_STATE_VM(qstr_mutex), 1)
#define QSTR_EXIT() mp_thread_mutex_unlock(&MP_STATE_VM(qstr_mutex))
#else
#define QSTR_ENTER()
#define QSTR_EXIT()
#endif
// Initial number of entries for qstr pool, set so that the first dynamically
// allocated pool is twice this size. The value here must be <= MP_QSTRnumber_of.
#define MICROPY_ALLOC_QSTR_ENTRIES_INIT (10)
// this must match the equivalent function in makeqstrdata.py
size_t qstr_compute_hash(const byte *data, size_t len) {
// djb2 algorithm; see http://www.cse.yorku.ca/~oz/hash.html
size_t hash = 5381;
for (const byte *top = data + len; data < top; data++) {
hash = ((hash << 5) + hash) ^ (*data); // hash * 33 ^ data
}
hash &= Q_HASH_MASK;
// Make sure that valid hash is never zero, zero means "hash not computed" if (hash == 0) {
hash++;
}
return hash;
}
const qstr_hash_t mp_qstr_const_hashes[] = {
#ifndef NO_QSTR
#define QDEF(id, hash, len, str) hash,
#include "genhdr/qstrdefs.generated.h"
#undef QDEF
#endif
};
const qstr_len_t mp_qstr_const_lengths[] = {
#ifndef NO_QSTR
#define QDEF(id, hash, len, str) len,
#include "genhdr/qstrdefs.generated.h"
#undef QDEF
#endif
};
const qstr_pool_t mp_qstr_const_pool = {
NULL, // no previous pool
0, // no previous pool
MICROPY_ALLOC_QSTR_ENTRIES_INIT,
MP_QSTRnumber_of, // corresponds to number of strings in array just below
(qstr_hash_t *)mp_qstr_const_hashes,
(qstr_len_t *)mp_qstr_const_lengths,
{
#ifndef NO_QSTR
#define QDEF(id, hash, len, str) str,
#include "genhdr/qstrdefs.generated.h"
#undef QDEF
#endif
},
};
#ifdef MICROPY_QSTR_EXTRA_POOL
extern const qstr_pool_t MICROPY_QSTR_EXTRA_POOL;
#define CONST_POOL MICROPY_QSTR_EXTRA_POOL
#else
#define CONST_POOL mp_qstr_const_pool
#endif
void qstr_init(void) {
MP_STATE_VM(last_pool) = (qstr_pool_t *)&CONST_POOL; // we won't modify the const_pool since it has no allocated room left
MP_STATE_VM(qstr_last_chunk) = NULL;
#if MICROPY_PY_THREAD && !MICROPY_PY_THREAD_GIL
mp_thread_mutex_init(&MP_STATE_VM(qstr_mutex));
#endif
}
STATIC const qstr_pool_t *find_qstr(qstr *q) {
// search pool for this qstr
// total_prev_len==0 in the final pool, so the loop will always terminate
const qstr_pool_t *pool = MP_STATE_VM(last_pool);
while (*q < pool->total_prev_len) {
pool = pool->prev;
}
*q -= pool->total_prev_len;
assert(*q < pool->len);
return pool;
}
// qstr_mutex must be taken while in this function
STATIC qstr qstr_add(mp_uint_t hash, mp_uint_t len, const char *q_ptr) {
printf("QSTR: add hash=%d len=%d data=%.*s\n", (int)hash, (int)len, (int)len, q_ptr);
// make sure we have room in the pool for a new qstr
if (MP_STATE_VM(last_pool)->len >= MP_STATE_VM(last_pool)->alloc) {
size_t new_alloc = MP_STATE_VM(last_pool)->alloc * 2;
#ifdef MICROPY_QSTR_EXTRA_POOL
// Put a lower bound on the allocation size in case the extra qstr pool has few entries
new_alloc = MAX(MICROPY_ALLOC_QSTR_ENTRIES_INIT, new_alloc);
#endif
mp_uint_t pool_size = sizeof(qstr_pool_t)
+ (sizeof(const char *) + sizeof(qstr_hash_t) + sizeof(qstr_len_t)) * new_alloc;
qstr_pool_t *pool = (qstr_pool_t *)m_malloc_maybe(pool_size);
if (pool == NULL) {
// Keep qstr_last_chunk consistent with qstr_pool_t: qstr_last_chunk is not scanned
// at garbage collection since it's reachable from a qstr_pool_t. And the caller of
// this function expects q_ptr to be stored in a qstr_pool_t so it can be reached
// by the collector. If qstr_pool_t allocation failed, qstr_last_chunk needs to be
// NULL'd. Otherwise it may become a dangling pointer at the next garbage collection.
MP_STATE_VM(qstr_last_chunk) = NULL;
QSTR_EXIT();
m_malloc_fail(new_alloc);
}
pool->hashes = (qstr_hash_t *)(pool->qstrs + new_alloc);
pool->lengths = (qstr_len_t *)(pool->hashes + new_alloc);
pool->prev = MP_STATE_VM(last_pool);
pool->total_prev_len = MP_STATE_VM(last_pool)->total_prev_len + MP_STATE_VM(last_pool)->len;
pool->alloc = new_alloc;
pool->len = 0;
MP_STATE_VM(last_pool) = pool;
DEBUG_printf("QSTR: allocate new pool of size %d\n", MP_STATE_VM(last_pool)->alloc);
}
// add the new qstr
mp_uint_t at = MP_STATE_VM(last_pool)->len;
MP_STATE_VM(last_pool)->hashes[at] = hash;
MP_STATE_VM(last_pool)->lengths[at] = len;
MP_STATE_VM(last_pool)->qstrs[at] = q_ptr;
MP_STATE_VM(last_pool)->len++;
// return id for the newly-added qstr
return MP_STATE_VM(last_pool)->total_prev_len + at;
}
qstr qstr_find_strn(const char *str, size_t str_len) {
// work out hash of str
size_t str_hash = qstr_compute_hash((const byte *)str, str_len);
// search pools for the data
for (const qstr_pool_t *pool = MP_STATE_VM(last_pool); pool != NULL; pool = pool->prev) {
for (mp_uint_t at = 0, top = pool->len; at < top; at++) {
if (pool->hashes[at] == str_hash && pool->lengths[at] == str_len
&& memcmp(pool->qstrs[at], str, str_len) == 0) {
return pool->total_prev_len + at;
}
}
}
// not found; return null qstr
return 0;
}
qstr qstr_from_str(const char *str) {
return qstr_from_strn(str, strlen(str));
}
qstr qstr_from_strn(const char *str, size_t len) {
QSTR_ENTER();
qstr q = qstr_find_strn(str, len);
if (q == 0) {
// qstr does not exist in interned pool so need to add it
// check that len is not too big if (len >= (1 << (8 * MICROPY_QSTR_BYTES_IN_LEN))) {
QSTR_EXIT();
mp_raise_msg(&mp_type_RuntimeError, MP_ERROR_TEXT("name too long"));
}
// compute number of bytes needed to intern this string
size_t n_bytes = len + 1;
if (MP_STATE_VM(qstr_last_chunk) != NULL && MP_STATE_VM(qstr_last_used) + n_bytes > MP_STATE_VM(qstr_last_alloc)) {
// not enough room at end of previously interned string so try to grow
char *new_p = m_renew_maybe(char, MP_STATE_VM(qstr_last_chunk), MP_STATE_VM(qstr_last_alloc), MP_STATE_VM(qstr_last_alloc) + n_bytes, false);
if (new_p == NULL) {
// could not grow existing memory; shrink it to fit previous
(void)m_renew_maybe(char, MP_STATE_VM(qstr_last_chunk), MP_STATE_VM(qstr_last_alloc), MP_STATE_VM(qstr_last_used), false);
MP_STATE_VM(qstr_last_chunk) = NULL;
} else {
// could grow existing memory
MP_STATE_VM(qstr_last_alloc) += n_bytes;
}
}
if (MP_STATE_VM(qstr_last_chunk) == NULL) {
// no existing memory for the interned string so allocate a new chunk
size_t al = n_bytes;
if (al < MICROPY_ALLOC_QSTR_CHUNK_INIT) {
al = MICROPY_ALLOC_QSTR_CHUNK_INIT;
}
MP_STATE_VM(qstr_last_chunk) = m_new_maybe(char, al);
if (MP_STATE_VM(qstr_last_chunk) == NULL) {
// failed to allocate a large chunk so try with exact size
MP_STATE_VM(qstr_last_chunk) = m_new_maybe(char, n_bytes);
if (MP_STATE_VM(qstr_last_chunk) == NULL) {
QSTR_EXIT();
m_malloc_fail(n_bytes);
}
al = n_bytes;
}
MP_STATE_VM(qstr_last_alloc) = al;
MP_STATE_VM(qstr_last_used) = 0;
}
// allocate memory from the chunk for this new interned string's data
char *q_ptr = MP_STATE_VM(qstr_last_chunk) + MP_STATE_VM(qstr_last_used);
MP_STATE_VM(qstr_last_used) += n_bytes;
// store the interned strings' data
size_t hash = qstr_compute_hash((const byte *)str, len);
memcpy(q_ptr, str, len);
q_ptr[len] = '\0';
q = qstr_add(hash, len, q_ptr);
}
QSTR_EXIT();
return q;
}
mp_uint_t qstr_hash(qstr q) {
const qstr_pool_t *pool = find_qstr(&q);
return pool->hashes[q];
}
size_t qstr_len(qstr q) {
const qstr_pool_t *pool = find_qstr(&q);
return pool->lengths[q];
}
const char *qstr_str(qstr q) {
const qstr_pool_t *pool = find_qstr(&q);
return pool->qstrs[q];
}
const byte *qstr_data(qstr q, size_t *len) {
const qstr_pool_t *pool = find_qstr(&q);
*len = pool->lengths[q];
return (byte *)pool->qstrs[q];
}
void qstr_pool_info(size_t *n_pool, size_t *n_qstr, size_t *n_str_data_bytes, size_t *n_total_bytes) {
QSTR_ENTER();
*n_pool = 0;
*n_qstr = 0;
*n_str_data_bytes = 0;
*n_total_bytes = 0;
for (const qstr_pool_t *pool = MP_STATE_VM(last_pool); pool != NULL && pool != &CONST_POOL; pool = pool->prev) {
*n_pool += 1;
*n_qstr += pool->len;
for (qstr_len_t *l = pool->lengths, *l_top = pool->lengths + pool->len; l < l_top; l++) {
*n_str_data_bytes += *l + 1;
}
#if MICROPY_ENABLE_GC
*n_total_bytes += gc_nbytes(pool); // this counts actual bytes used in heap
#else
*n_total_bytes += sizeof(qstr_pool_t)
+ (sizeof(const char *) + sizeof(qstr_hash_t) + sizeof(qstr_len_t)) * pool->alloc;
#endif
}
*n_total_bytes += *n_str_data_bytes;
QSTR_EXIT();
}
#if MICROPY_PY_MICROPYTHON_MEM_INFO
void qstr_dump_data(void) {
QSTR_ENTER();
for (const qstr_pool_t *pool = MP_STATE_VM(last_pool); pool != NULL && pool != &CONST_POOL; pool = pool->prev) {
for (const char *const *q = pool->qstrs, *const *q_top = pool->qstrs + pool->len; q < q_top; q++) {
mp_printf(&mp_plat_print, "Q(%s)\n", *q);
}
}
QSTR_EXIT();
}
#endif
#if MICROPY_ROM_TEXT_COMPRESSION
#ifdef NO_QSTR
// If NO_QSTR is set, it means we're doing QSTR extraction.
// So we won't yet have "genhdr/compressed.data.h"
#else
// Emit the compressed_string_data string.
#define MP_COMPRESSED_DATA(x) STATIC const char *compressed_string_data = x;
#define MP_MATCH_COMPRESSED(a, b)
#include "genhdr/compressed.data.h"
#undef MP_COMPRESSED_DATA
#undef MP_MATCH_COMPRESSED
#endif // NO_QSTR
// This implements the "common word" compression scheme (see makecompresseddata.py) where the most
// common 128 words in error messages are replaced by their index into the list of common words.
// The compressed string data is delimited by setting high bit in the final char of each word.
// e.g. aaaa<0x80|a>bbbbbb<0x80|b>....
// This method finds the n'th string.
STATIC const byte *find_uncompressed_string(uint8_t n) {
const byte *c = (byte *)compressed_string_data;
while (n > 0) {
while ((*c & 0x80) == 0) {
++c; }
++c;
--n;
}
return c;
}
// Given a compressed string in src, decompresses it into dst.
// dst must be large enough (use MP_MAX_UNCOMPRESSED_TEXT_LEN+1).
void mp_decompress_rom_string(byte *dst, const mp_rom_error_text_t src_chr) {
// Skip past the 0xff marker.
const byte *src = (byte *)src_chr + 1;
// Need to add spaces around compressed words, except for the first (i.e. transition from 1<->2).
// 0 = start, 1 = compressed, 2 = regular.
int state = 0;
while (*src) {
if ((byte) * src >= 128) {
if (state != 0) {
*dst++ = ' ';
}
state = 1;
// High bit set, replace with common word.
const byte *word = find_uncompressed_string(*src & 0x7f);
// The word is terminated by the final char having its high bit set.
while ((*word & 0x80) == 0) {
*dst++ = *word++;
}
*dst++ = (*word & 0x7f);
} else {
// Otherwise just copy one char.
if (state == 1) {
*dst++ = ' ';
}
state = 2;
*dst++ = *src;
}
++src;
}
// Add null-terminator.
*dst = 0;
}
#endif // MICROPY_ROM_TEXT_COMPRESSION