add locks + file alloc in Writer::finish

Cargo.lock

@@ -51,9 +51,9 @@ checksum = "8a32fd6af2b5827bce66c29053ba0e7c42b9dcab01835835058558c10851a46b"
 
 [[package]]
 name = "bincode"
-version = "2.0.0-rc.2"
+version = "2.0.0-rc.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7bb50c5a2ef4b9b1e7ae73e3a73b52ea24b20312d629f9c4df28260b7ad2c3c4"
+checksum = "f11ea1a0346b94ef188834a65c068a03aec181c94896d481d7a0a40d85b0ce95"
 dependencies = [
  "bincode_derive",
  "serde",
@@ -61,9 +61,9 @@ dependencies = [
 
 [[package]]
 name = "bincode_derive"
-version = "2.0.0-rc.2"
+version = "2.0.0-rc.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a45a23389446d2dd25dc8e73a7a3b3c43522b630cac068927f0649d43d719d2"
+checksum = "7e30759b3b99a1b802a7a3aa21c85c3ded5c28e1c83170d82d70f08bbf7f3e4c"
 dependencies = [
  "virtue",
 ]
@@ -76,9 +76,9 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "block-buffer"
-version = "0.10.3"
+version = "0.10.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "69cce20737498f97b993470a6e536b8523f0af7892a4f928cceb1ac5e52ebe7e"
+checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
 dependencies = [
  "generic-array",
 ]
@@ -158,6 +158,7 @@ name = "chgk_ledb_lib"
 version = "1.1.0"
 dependencies = [
  "bincode",
+ "fs4",
  "memmap",
  "serde",
  "serde_derive",
@@ -230,7 +231,7 @@ dependencies = [
  "proc-macro-error",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.109",
 ]
 
 [[package]]
@@ -250,9 +251,9 @@ checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
 
 [[package]]
 name = "cpufeatures"
-version = "0.2.5"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28d997bd5e24a5928dd43e46dc529867e207907fe0b239c3477d924f7f2ca320"
+checksum = "280a9f2d8b3a38871a3c8a46fb80db65e5e5ed97da80c4d08bf27fb63e35e181"
 dependencies = [
  "libc",
 ]
@@ -383,6 +384,17 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "errno"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "50d6a0976c999d473fe89ad888d5a284e55366d9dc9038b1ba2aa15128c4afa0"
+dependencies = [
+ "errno-dragonfly",
+ "libc",
+ "windows-sys 0.45.0",
+]
+
 [[package]]
 name = "errno-dragonfly"
 version = "0.1.2"
@@ -413,10 +425,21 @@ dependencies = [
 ]
 
 [[package]]
-name = "generic-array"
-version = "0.14.6"
+name = "fs4"
+version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bff49e947297f3312447abdca79f45f4738097cc82b06e72054d2223f601f1b9"
+checksum = "8ea55201cc351fdb478217c0fb641b59813da9b4efe4c414a9d8f989a657d149"
+dependencies = [
+ "libc",
+ "rustix 0.35.13",
+ "winapi",
+]
+
+[[package]]
+name = "generic-array"
+version = "0.14.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
 dependencies = [
  "typenum",
  "version_check",
@@ -469,6 +492,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "hermit-abi"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fed44880c466736ef9a5c5b5facefb5ed0785676d0c02d612db14e54f0d84286"
+
 [[package]]
 name = "hmac"
 version = "0.12.1"
@@ -480,9 +509,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "1.9.2"
+version = "1.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1885e79c1fc4b10f0e172c475f458b7f7b93061064d98c3293e98c5ba0c8b399"
+checksum = "bd070e393353796e801d209ad339e89596eb4c8d430d18ede6a1cced8fafbd99"
 dependencies = [
  "autocfg",
  "hashbrown",
@@ -499,10 +528,17 @@ dependencies = [
 
 [[package]]
 name = "io-lifetimes"
-version = "1.0.5"
+version = "0.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1abeb7a0dd0f8181267ff8adc397075586500b81b28a73e8a0208b00fc170fb3"
+checksum = "59ce5ef949d49ee85593fc4d3f3f95ad61657076395cbbce23e2121fc5542074"
+
+[[package]]
+name = "io-lifetimes"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09270fd4fa1111bc614ed2246c7ef56239a3063d5be0d1ec3b589c505d400aeb"
 dependencies = [
+ "hermit-abi 0.3.1",
  "libc",
  "windows-sys 0.45.0",
 ]
@@ -518,9 +554,9 @@ dependencies = [
 
 [[package]]
 name = "itoa"
-version = "1.0.5"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fad582f4b9e86b6caa621cabeb0963332d92eea04729ab12892c2533951e6440"
+checksum = "453ad9f582a441959e5f0d088b02ce04cfe8d51a8eaf077f12ac6d3e94164ca6"
 
 [[package]]
 name = "jobserver"
@@ -548,15 +584,21 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.139"
+version = "0.2.140"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "201de327520df007757c1f0adce6e827fe8562fbc28bfd9c15571c66ca1f5f79"
+checksum = "99227334921fae1a979cf0bfdfcc6b3e5ce376ef57e16fb6fb3ea2ed6095f80c"
 
 [[package]]
 name = "linux-raw-sys"
-version = "0.1.4"
+version = "0.0.46"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f051f77a7c8e6957c0696eac88f26b0117e54f52d3fc682ab19397a8812846a4"
+checksum = "d4d2456c373231a208ad294c33dc5bff30051eafd954cd4caae83a712b12854d"
+
+[[package]]
+name = "linux-raw-sys"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d59d8c75012853d2e872fb56bc8a2e53718e2cafe1a4c823143141c6d90c322f"
 
 [[package]]
 name = "log"
@@ -634,9 +676,9 @@ checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
 
 [[package]]
 name = "os_str_bytes"
-version = "6.4.1"
+version = "6.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b7820b9daea5457c9f21c69448905d723fbd21136ccf521748f23fd49e723ee"
+checksum = "ceedf44fb00f2d1984b0bc98102627ce622e083e49a5bacdb3e514fa4238e267"
 
 [[package]]
 name = "password-hash"
@@ -710,7 +752,7 @@ dependencies = [
  "proc-macro-error-attr",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.109",
  "version_check",
 ]
 
@@ -727,18 +769,18 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.51"
+version = "1.0.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d727cae5b39d21da60fa540906919ad737832fe0b1c165da3a34d6548c849d6"
+checksum = "2b63bdb0cd06f1f4dedf69b254734f9b45af66e4a031e42a7480257d9898b435"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.23"
+version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8856d8364d252a14d474036ea1358d63c9e6965c8e5c1885c18f73d70bff9c7b"
+checksum = "4424af4bf778aae2051a77b60283332f386554255d722233d09fbfc7e30da2fc"
 dependencies = [
  "proc-macro2",
 ]
@@ -775,9 +817,9 @@ dependencies = [
 
 [[package]]
 name = "rayon"
-version = "1.6.1"
+version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6db3a213adf02b3bcfd2d3846bb41cb22857d131789e01df434fb7e7bc0759b7"
+checksum = "1d2df5196e37bcc87abebc0053e20787d73847bb33134a69841207dd0a47f03b"
 dependencies = [
  "either",
  "rayon-core",
@@ -785,9 +827,9 @@ dependencies = [
 
 [[package]]
 name = "rayon-core"
-version = "1.10.2"
+version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "356a0625f1954f730c0201cdab48611198dc6ce21f4acff55089b5a78e6e835b"
+checksum = "4b8f95bd6966f5c87776639160a66bd8ab9895d9d4ab01ddba9fc60661aebe8d"
 dependencies = [
  "crossbeam-channel",
  "crossbeam-deque",
@@ -797,47 +839,61 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.2.16"
+version = "0.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fb5a58c1855b4b6819d59012155603f0b22ad30cad752600aadfcb695265519a"
+checksum = "567664f262709473930a4bf9e51bf2ebf3348f2e748ccc50dea20646858f8f29"
 dependencies = [
  "bitflags",
 ]
 
 [[package]]
 name = "regex"
-version = "1.7.1"
+version = "1.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "48aaa5748ba571fb95cd2c85c09f629215d3a6ece942baa100950af03a34f733"
+checksum = "8b1f693b24f6ac912f4893ef08244d70b6067480d2f1a46e950c9691e6749d1d"
 dependencies = [
  "regex-syntax",
 ]
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.28"
+version = "0.6.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "456c603be3e8d448b072f410900c09faf164fbce2d480456f50eea6e25f9c848"
+checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
 
 [[package]]
 name = "rustix"
-version = "0.36.8"
+version = "0.35.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f43abb88211988493c1abb44a70efa56ff0ce98f233b7b276146f1f3f7ba9644"
+checksum = "727a1a6d65f786ec22df8a81ca3121107f235970dc1705ed681d3e6e8b9cd5f9"
 dependencies = [
  "bitflags",
- "errno",
- "io-lifetimes",
+ "errno 0.2.8",
+ "io-lifetimes 0.7.5",
  "libc",
- "linux-raw-sys",
+ "linux-raw-sys 0.0.46",
+ "windows-sys 0.42.0",
+]
+
+[[package]]
+name = "rustix"
+version = "0.37.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d097081ed288dfe45699b72f5b5d648e5f15d64d900c7080273baa20c16a6849"
+dependencies = [
+ "bitflags",
+ "errno 0.3.0",
+ "io-lifetimes 1.0.9",
+ "libc",
+ "linux-raw-sys 0.3.1",
  "windows-sys 0.45.0",
 ]
 
 [[package]]
 name = "ryu"
-version = "1.0.12"
+version = "1.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b4b9743ed687d4b4bcedf9ff5eaa7398495ae14e61cba0a295704edbc7decde"
+checksum = "f91339c0467de62360649f8d3e185ca8de4224ff281f66000de5eb2a77a79041"
 
 [[package]]
 name = "same-file"
@@ -856,29 +912,29 @@ checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
 [[package]]
 name = "serde"
-version = "1.0.152"
+version = "1.0.159"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bb7d1f0d3021d347a83e556fc4683dea2ea09d87bccdf88ff5c12545d89d5efb"
+checksum = "3c04e8343c3daeec41f58990b9d77068df31209f2af111e059e9fe9646693065"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.152"
+version = "1.0.159"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af487d118eecd09402d70a5d72551860e788df87b464af30e5ea6a38c75c541e"
+checksum = "4c614d17805b093df4b147b51339e7e44bf05ef59fba1e45d83500bcfb4d8585"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.13",
 ]
 
 [[package]]
 name = "serde_json"
-version = "1.0.93"
+version = "1.0.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cad406b69c91885b5107daf2c29572f6c8cdb3c66826821e286c533490c0bc76"
+checksum = "d721eca97ac802aa7777b701877c8004d950fc142651367300d21c1cc0194744"
 dependencies = [
  "itoa",
  "ryu",
@@ -931,16 +987,27 @@ dependencies = [
 ]
 
 [[package]]
-name = "tempfile"
-version = "3.4.0"
+name = "syn"
+version = "2.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af18f7ae1acd354b992402e9ec5864359d693cd8a79dcbef59f76891701c1e95"
+checksum = "4c9da457c5285ac1f936ebd076af6dac17a61cfe7826f2076b4d015cf47bc8ec"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "tempfile"
+version = "3.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9fbec84f381d5795b08656e4912bec604d162bff9291d6189a78f4c8ab87998"
 dependencies = [
  "cfg-if",
  "fastrand",
  "redox_syscall",
- "rustix",
- "windows-sys 0.42.0",
+ "rustix 0.37.6",
+ "windows-sys 0.45.0",
 ]
 
 [[package]]
@@ -1003,9 +1070,9 @@ checksum = "497961ef93d974e23eb6f433eb5fe1b7930b659f06d12dec6fc44a8f554c0bba"
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.6"
+version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "84a22b9f218b40614adcb3f4ff08b703773ad44fa9423e4e0d346d5db86e4ebc"
+checksum = "e5464a87b239f13a63a501f2701565754bae92d243d4bb7eb12f6d57d2269bf4"
 
 [[package]]
 name = "version_check"
@@ -1015,18 +1082,17 @@ checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
 [[package]]
 name = "virtue"
-version = "0.0.8"
+version = "0.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b60dcd6a64dd45abf9bd426970c9843726da7fc08f44cd6fcebf68c21220a63"
+checksum = "9dcc60c0624df774c82a0ef104151231d37da4962957d691c011c852b2473314"
 
 [[package]]
 name = "walkdir"
-version = "2.3.2"
+version = "2.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "808cf2735cd4b6866113f648b791c6adc5714537bc222d9347bb203386ffda56"
+checksum = "36df944cda56c7d8d8b7496af378e6b16de9284591917d307c9b4d313c44e698"
 dependencies = [
  "same-file",
- "winapi",
  "winapi-util",
 ]
 
@@ -1057,7 +1123,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.109",
  "wasm-bindgen-shared",
 ]
 
@@ -1079,7 +1145,7 @@ checksum = "2aff81306fcac3c7515ad4e177f521b5c9a15f2b08f4e32d823066102f35a5f6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.109",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
@@ -1157,9 +1223,9 @@ dependencies = [
 
 [[package]]
 name = "windows-targets"
-version = "0.42.1"
+version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e2522491fbfcd58cc84d47aeb2958948c4b8982e9a2d8a2a35bbaed431390e7"
+checksum = "8e5180c00cd44c9b1c88adb3693291f1cd93605ded80c250a75d472756b4d071"
 dependencies = [
  "windows_aarch64_gnullvm",
  "windows_aarch64_msvc",
@@ -1172,45 +1238,45 @@ dependencies = [
 
 [[package]]
 name = "windows_aarch64_gnullvm"
-version = "0.42.1"
+version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c9864e83243fdec7fc9c5444389dcbbfd258f745e7853198f365e3c4968a608"
+checksum = "597a5118570b68bc08d8d59125332c54f1ba9d9adeedeef5b99b02ba2b0698f8"
 
 [[package]]
 name = "windows_aarch64_msvc"
-version = "0.42.1"
+version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c8b1b673ffc16c47a9ff48570a9d85e25d265735c503681332589af6253c6c7"
+checksum = "e08e8864a60f06ef0d0ff4ba04124db8b0fb3be5776a5cd47641e942e58c4d43"
 
 [[package]]
 name = "windows_i686_gnu"
-version = "0.42.1"
+version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "de3887528ad530ba7bdbb1faa8275ec7a1155a45ffa57c37993960277145d640"
+checksum = "c61d927d8da41da96a81f029489353e68739737d3beca43145c8afec9a31a84f"
 
 [[package]]
 name = "windows_i686_msvc"
-version = "0.42.1"
+version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf4d1122317eddd6ff351aa852118a2418ad4214e6613a50e0191f7004372605"
+checksum = "44d840b6ec649f480a41c8d80f9c65108b92d89345dd94027bfe06ac444d1060"
 
 [[package]]
 name = "windows_x86_64_gnu"
-version = "0.42.1"
+version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1040f221285e17ebccbc2591ffdc2d44ee1f9186324dd3e84e99ac68d699c45"
+checksum = "8de912b8b8feb55c064867cf047dda097f92d51efad5b491dfb98f6bbb70cb36"
 
 [[package]]
 name = "windows_x86_64_gnullvm"
-version = "0.42.1"
+version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "628bfdf232daa22b0d64fdb62b09fcc36bb01f05a3939e20ab73aaf9470d0463"
+checksum = "26d41b46a36d453748aedef1486d5c7a85db22e56aff34643984ea85514e94a3"
 
 [[package]]
 name = "windows_x86_64_msvc"
-version = "0.42.1"
+version = "0.42.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "447660ad36a13288b1db4d4248e857b510e8c3a225c822ba4fb748c0aafecffd"
+checksum = "9aec5da331524158c6d1a4ac0ab1541149c0b9505fde06423b02f5ef0106b9f0"
 
 [[package]]
 name = "zip"

app/benches/db_bench.rs

@@ -7,12 +7,12 @@ extern crate serde_json;
 extern crate tempfile;
 
 use chgk_ledb_lib::db;
-use std::path::PathBuf;
+use std::path::Path;
 
 use db::{Reader, Writer, WriterOpts};
 
 use criterion::{BatchSize, Criterion};
-use tempfile::tempdir;
+use tempfile::{tempdir, NamedTempFile};
 
 use serde_derive::{Deserialize, Serialize};
 
@@ -37,17 +37,14 @@ struct TestData {
 const N: usize = 4096;
 
 fn gen_data(count: usize) -> impl Iterator<Item = TestData> {
-    (0..count)
-        .into_iter()
-        .map(|i| 143 + i as u64)
-        .map(|i| TestData {
-            num1: i,
-            num2: i * 100 ^ 0xDF0E441122334455,
-            test: "test ---- Test ____".repeat(123 + i as usize % 15),
-        })
+    (0..count).map(|i| 143 + i as u64).map(|i| TestData {
+        num1: i,
+        num2: (i * 100) ^ 0xDF0E441122334455,
+        test: "test ---- Test ____".repeat(123 + i as usize % 15),
+    })
 }
 
-fn prepare_db_writer(path: &PathBuf) -> Writer<TestData> {
+fn prepare_db_writer<P: AsRef<Path>>(path: P) -> Writer<TestData> {
     let opts = WriterOpts {
         compress_lvl: 1,
         data_buf_size: 100 * 1024 * 1024,
@@ -60,7 +57,9 @@ fn prepare_db_writer(path: &PathBuf) -> Writer<TestData> {
 
 fn db_read(c: &mut Criterion) {
     let dir = tempdir().expect("tempdir");
-    let tmpfile = dir.path().join("test.tmp");
+    let tmpfile = NamedTempFile::new_in(dir.path())
+        .expect("new tempfile")
+        .into_temp_path();
     let mut writer = prepare_db_writer(&tmpfile);
 
     let mut items_iter = gen_data(N).collect::<Vec<TestData>>().into_iter();
@@ -85,10 +84,13 @@ fn db_read(c: &mut Criterion) {
 
 fn db_write(c: &mut Criterion) {
     let dir = tempdir().expect("tempdir");
-    let tmpfile = dir.path().join("test.tmp");
+
     c.bench_function("write", |b| {
         b.iter_batched(
             || {
+                let tmpfile = NamedTempFile::new_in(dir.path())
+                    .expect("new tempfile")
+                    .into_temp_path();
                 let src = gen_data(N).collect::<Vec<TestData>>().into_iter();
                 let writer = prepare_db_writer(&tmpfile);
                 (src, writer)

lib/Cargo.toml

@@ -17,6 +17,7 @@ zip="0.6"
 bincode = "^2.0.0-rc.2"
 zstd = "^0.10"
 memmap = "0.7.0"
+fs4 = { version = "0.6.3", features = ["sync"] }
 
 [dev-dependencies]
 tempfile = "3.3"

lib/src/db.rs

@@ -8,6 +8,8 @@ use std::{
 
 use memmap::{Mmap, MmapOptions};
 
+use fs4::FileExt;
+
 type LSize = u32;
 const LEN_SIZE: usize = std::mem::size_of::<LSize>();
 const BINCODE_CFG: bincode::config::Configuration = bincode::config::standard();
@@ -63,6 +65,7 @@ where
 {
     pub fn new<P: AsRef<Path>>(path: P, opts: WriterOpts) -> Result<Self, String> {
         let out = fs::File::create(path).str_err()?;
+        out.try_lock_exclusive().str_err()?;
         let out = io::BufWriter::with_capacity(opts.out_buf_size, out);
         let data_buf: Vec<u8> = Vec::with_capacity(opts.data_buf_size);
         let data_buf = Cursor::new(data_buf);
@@ -133,6 +136,9 @@ where
         let pos: LSize = self.data_buf.position() as LSize;
         self.table.push(pos);
 
+        let output_size: u64 = (self.table.len() * LEN_SIZE) as u64 + self.data_buf.position();
+        self.out.get_ref().allocate(output_size).str_err()?;
+
         // write tab
         let tab_size = (self.table.len() * LEN_SIZE) as LSize;
         for pos in self.table {
@@ -147,6 +153,7 @@ where
         io::copy(&mut data, &mut self.out).str_err()?;
 
         self.out.flush().str_err()?;
+        self.out.get_ref().unlock().str_err()?;
         Ok(())
     }
 }
@@ -167,6 +174,7 @@ where
 {
     pub fn new<P: AsRef<Path>>(path: P, _buf_size: usize) -> Result<Self, String> {
         let file = fs::File::open(path).str_err()?;
+        file.try_lock_shared().str_err()?;
         let mmap = unsafe { MmapOptions::new().map(&file).str_err()? };
 
         // read first pos and records count