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-rw-r--r--py/qstr.c156
1 files changed, 116 insertions, 40 deletions
diff --git a/py/qstr.c b/py/qstr.c
index 93ae3ab665..2830341a2d 100644
--- a/py/qstr.c
+++ b/py/qstr.c
@@ -2,7 +2,8 @@
#include <string.h>
#include "misc.h"
-#include "mpqstr.h"
+#include "mpconfig.h"
+#include "qstr.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
@@ -15,12 +16,33 @@
#define DEBUG_printf(args...) (void)0
#endif
+// A qstr is an index into the qstr pool.
+// The data for a qstr contains (hash, length, data).
+// For now we use very simple encoding, just to get the framework correct:
+// - hash is 2 bytes (simply the sum of data bytes)
+// - length is 2 bytes
+// - data follows
+// - \0 terminated (for now, so they can be printed using printf)
+
+#define Q_GET_HASH(q) ((q)[0] | ((q)[1] << 8))
+#define Q_GET_ALLOC(q) (4 + Q_GET_LENGTH(q) + 1)
+#define Q_GET_LENGTH(q) ((q)[2] | ((q)[3] << 8))
+#define Q_GET_DATA(q) ((q) + 4)
+
+static machine_uint_t compute_hash(const byte *data, uint len) {
+ machine_uint_t hash = 0;
+ for (const byte *top = data + len; data < top; data++) {
+ hash += *data;
+ }
+ return hash & 0xffff;
+}
+
typedef struct _qstr_pool_t {
struct _qstr_pool_t *prev;
uint total_prev_len;
uint alloc;
uint len;
- const char *qstrs[];
+ const byte *qstrs[];
} qstr_pool_t;
const static qstr_pool_t const_pool = {
@@ -29,9 +51,11 @@ const static qstr_pool_t const_pool = {
10, // set so that the first dynamically allocated pool is twice this size; must be <= the len (just below)
MP_QSTR_number_of, // corresponds to number of strings in array just below
{
- "nil", // must be first, since 0 qstr is nil
-#define Q(id) #id,
-#include "mpqstrraw.h"
+ (const byte*) "\0\0\0\0", // invalid/no qstr has empty data
+ (const byte*) "\0\0\0\0", // empty qstr
+#define Q(id, str) str,
+// TODO having 'build/' here is a bit of a hack, should take config variable from Makefile
+#include "build/py.qstrdefs.generated.h"
#undef Q
},
};
@@ -42,8 +66,20 @@ void qstr_init(void) {
last_pool = (qstr_pool_t*)&const_pool; // we won't modify the const_pool since it has no allocated room left
}
-static qstr qstr_add(const char *str) {
- DEBUG_printf("QSTR: add %s\n", str);
+static const byte *find_qstr(qstr q) {
+ // search pool for this qstr
+ for (qstr_pool_t *pool = last_pool; pool != NULL; pool = pool->prev) {
+ if (q >= pool->total_prev_len) {
+ return pool->qstrs[q - pool->total_prev_len];
+ }
+ }
+
+ // not found
+ return 0;
+}
+
+static qstr qstr_add(const byte *q_ptr) {
+ DEBUG_printf("QSTR: add hash=%d len=%d data=%.*s\n", Q_GET_HASH(q_ptr), Q_GET_LENGTH(q_ptr), Q_GET_LENGTH(q_ptr), Q_GET_DATA(q_ptr));
// make sure we have room in the pool for a new qstr
if (last_pool->len >= last_pool->alloc) {
@@ -57,55 +93,95 @@ static qstr qstr_add(const char *str) {
}
// add the new qstr
- last_pool->qstrs[last_pool->len++] = str;
+ last_pool->qstrs[last_pool->len++] = q_ptr;
// return id for the newly-added qstr
return last_pool->total_prev_len + last_pool->len - 1;
}
-qstr qstr_from_str_static(const char *str) {
+static qstr qstr_find_strn(const byte *str, uint str_len) {
+ // work out hash of str
+ machine_uint_t str_hash = compute_hash((const byte*)str, str_len);
+
+ // search pools for the data
for (qstr_pool_t *pool = last_pool; pool != NULL; pool = pool->prev) {
- for (const char **qstr = pool->qstrs, **qstr_top = pool->qstrs + pool->len; qstr < qstr_top; qstr++) {
- if (strcmp(*qstr, str) == 0) {
- return pool->total_prev_len + (qstr - pool->qstrs);
+ for (const byte **q = pool->qstrs, **q_top = pool->qstrs + pool->len; q < q_top; q++) {
+ if (Q_GET_HASH(*q) == str_hash && Q_GET_LENGTH(*q) == str_len && strncmp((const char*)Q_GET_DATA(*q), (const char*)str, str_len) == 0) {
+ return pool->total_prev_len + (q - pool->qstrs);
}
}
}
- return qstr_add(str);
+
+ // not found; return null qstr
+ return 0;
}
-qstr qstr_from_str_take(char *str, int alloc_len) {
- for (qstr_pool_t *pool = last_pool; pool != NULL; pool = pool->prev) {
- for (const char **qstr = pool->qstrs, **qstr_top = pool->qstrs + pool->len; qstr < qstr_top; qstr++) {
- if (strcmp(*qstr, str) == 0) {
- m_del(char, str, alloc_len);
- return pool->total_prev_len + (qstr - pool->qstrs);
- }
- }
- }
- return qstr_add(str);
+qstr qstr_from_str(const char *str) {
+ return qstr_from_strn(str, strlen(str));
}
-qstr qstr_from_strn_copy(const char *str, int len) {
- for (qstr_pool_t *pool = last_pool; pool != NULL; pool = pool->prev) {
- for (const char **qstr = pool->qstrs, **qstr_top = pool->qstrs + pool->len; qstr < qstr_top; qstr++) {
- if (strncmp(*qstr, str, len) == 0 && (*qstr)[len] == '\0') {
- return pool->total_prev_len + (qstr - pool->qstrs);
- }
- }
+qstr qstr_from_strn(const char *str, uint len) {
+ qstr q = qstr_find_strn((const byte*)str, len);
+ if (q == 0) {
+ machine_uint_t hash = compute_hash((const byte*)str, len);
+ byte *q_ptr = m_new(byte, 4 + len + 1);
+ q_ptr[0] = hash;
+ q_ptr[1] = hash >> 8;
+ q_ptr[2] = len;
+ q_ptr[3] = len >> 8;
+ memcpy(q_ptr + 4, str, len);
+ q_ptr[4 + len] = '\0';
+ q = qstr_add(q_ptr);
}
- return qstr_add(strndup(str, len));
+ return q;
}
-// convert qstr id to pointer to its string
-const char *qstr_str(qstr qstr) {
- // search
- for (qstr_pool_t *pool = last_pool; pool != NULL; pool = pool->prev) {
- if (qstr >= pool->total_prev_len) {
- return pool->qstrs[qstr - pool->total_prev_len];
- }
+qstr qstr_from_strn_take(char *str, uint alloc_len, uint len) {
+ qstr q = qstr_from_strn(str, len);
+ m_del(char, str, alloc_len);
+ return q;
+}
+
+byte *qstr_build_start(uint len, byte **q_ptr) {
+ assert(len <= 65535);
+ *q_ptr = m_new(byte, 4 + len + 1);
+ (*q_ptr)[2] = len;
+ (*q_ptr)[3] = len >> 8;
+ return Q_GET_DATA(*q_ptr);
+}
+
+qstr qstr_build_end(byte *q_ptr) {
+ qstr q = qstr_find_strn(Q_GET_DATA(q_ptr), Q_GET_LENGTH(q_ptr));
+ if (q == 0) {
+ machine_uint_t len = Q_GET_LENGTH(q_ptr);
+ machine_uint_t hash = compute_hash(Q_GET_DATA(q_ptr), len);
+ q_ptr[0] = hash;
+ q_ptr[1] = hash >> 8;
+ q_ptr[4 + len] = '\0';
+ q = qstr_add(q_ptr);
+ } else {
+ m_del(byte, q_ptr, Q_GET_ALLOC(q_ptr));
}
+ return q;
+}
+
+machine_uint_t qstr_hash(qstr q) {
+ return Q_GET_HASH(find_qstr(q));
+}
+
+uint qstr_len(qstr q) {
+ const byte *qd = find_qstr(q);
+ return Q_GET_LENGTH(qd);
+}
+
+// XXX to remove!
+const char *qstr_str(qstr q) {
+ const byte *qd = find_qstr(q);
+ return (const char*)Q_GET_DATA(qd);
+}
- // not found, return nil
- return const_pool.qstrs[0];
+const byte *qstr_data(qstr q, uint *len) {
+ const byte *qd = find_qstr(q);
+ *len = Q_GET_LENGTH(qd);
+ return Q_GET_DATA(qd);
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-06 18:38:13 +0000